Adding upstream version 124.0.1.upstream/124.0.1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 7276 insertions, 0 deletions

diff --git a/layout/tables/nsTableFrame.cpp b/layout/tables/nsTableFrame.cpp
new file mode 100644
index 0000000000..9a359192c0
--- /dev/null
+++ b/layout/tables/nsTableFrame.cpp
@@ -0,0 +1,7276 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=2 sw=2 et tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsTableFrame.h"
+
+#include "mozilla/gfx/2D.h"
+#include "mozilla/gfx/Helpers.h"
+#include "mozilla/Likely.h"
+#include "mozilla/MathAlgorithms.h"
+#include "mozilla/IntegerRange.h"
+#include "mozilla/PresShell.h"
+#include "mozilla/PresShellInlines.h"
+#include "mozilla/WritingModes.h"
+
+#include "gfxContext.h"
+#include "nsCOMPtr.h"
+#include "mozilla/ComputedStyle.h"
+#include "nsIFrameInlines.h"
+#include "nsFrameList.h"
+#include "nsStyleConsts.h"
+#include "nsIContent.h"
+#include "nsCellMap.h"
+#include "nsTableCellFrame.h"
+#include "nsHTMLParts.h"
+#include "nsTableColFrame.h"
+#include "nsTableColGroupFrame.h"
+#include "nsTableRowFrame.h"
+#include "nsTableRowGroupFrame.h"
+#include "nsTableWrapperFrame.h"
+
+#include "BasicTableLayoutStrategy.h"
+#include "FixedTableLayoutStrategy.h"
+
+#include "nsPresContext.h"
+#include "nsContentUtils.h"
+#include "nsCSSRendering.h"
+#include "nsGkAtoms.h"
+#include "nsCSSAnonBoxes.h"
+#include "nsIScriptError.h"
+#include "nsFrameManager.h"
+#include "nsError.h"
+#include "nsCSSFrameConstructor.h"
+#include "mozilla/Range.h"
+#include "mozilla/RestyleManager.h"
+#include "mozilla/ServoStyleSet.h"
+#include "nsDisplayList.h"
+#include "nsIScrollableFrame.h"
+#include "nsCSSProps.h"
+#include "nsLayoutUtils.h"
+#include "nsStyleChangeList.h"
+#include <algorithm>
+
+#include "mozilla/layers/StackingContextHelper.h"
+#include "mozilla/layers/RenderRootStateManager.h"
+
+using namespace mozilla;
+using namespace mozilla::image;
+using namespace mozilla::layout;
+
+using mozilla::gfx::AutoRestoreTransform;
+using mozilla::gfx::DrawTarget;
+using mozilla::gfx::Float;
+using mozilla::gfx::ToDeviceColor;
+
+namespace mozilla {
+
+struct TableReflowInput final {
+  TableReflowInput(const ReflowInput& aReflowInput,
+                   const LogicalMargin& aBorderPadding, TableReflowMode aMode)
+      : mReflowInput(aReflowInput),
+        mWM(aReflowInput.GetWritingMode()),
+        mAvailSize(mWM) {
+    MOZ_ASSERT(mReflowInput.mFrame->IsTableFrame(),
+               "TableReflowInput should only be created for nsTableFrame");
+    auto* table = static_cast<nsTableFrame*>(mReflowInput.mFrame);
+
+    mICoord = aBorderPadding.IStart(mWM) + table->GetColSpacing(-1);
+    mAvailSize.ISize(mWM) =
+        std::max(0, mReflowInput.ComputedISize() - table->GetColSpacing(-1) -
+                        table->GetColSpacing(table->GetColCount()));
+
+    // Bug 1863421 will fix border-spacing issue in the block-axis in printing.
+    mAvailSize.BSize(mWM) = aMode == TableReflowMode::Measuring
+                                ? NS_UNCONSTRAINEDSIZE
+                                : mReflowInput.AvailableBSize();
+    AdvanceBCoord(aBorderPadding.BStart(mWM));
+    ReduceAvailableBSizeBy(aBorderPadding.BEnd(mWM) + table->GetRowSpacing(-1) +
+                           table->GetRowSpacing(table->GetRowCount()));
+  }
+
+  // Advance to the next block-offset and reduce the available block-size.
+  void AdvanceBCoord(nscoord aAmount) {
+    mBCoord += aAmount;
+    ReduceAvailableBSizeBy(aAmount);
+  }
+
+  const LogicalSize& AvailableSize() const { return mAvailSize; }
+
+  // The real reflow input of the table frame.
+  const ReflowInput& mReflowInput;
+
+  // Stationary inline-offset, which won't change after the constructor.
+  nscoord mICoord = 0;
+
+  // Running block-offset, which will be adjusted as we reflow children.
+  nscoord mBCoord = 0;
+
+ private:
+  void ReduceAvailableBSizeBy(nscoord aAmount) {
+    if (mAvailSize.BSize(mWM) == NS_UNCONSTRAINEDSIZE) {
+      return;
+    }
+    mAvailSize.BSize(mWM) -= aAmount;
+    mAvailSize.BSize(mWM) = std::max(0, mAvailSize.BSize(mWM));
+  }
+
+  // mReflowInput's (i.e. table frame's) writing-mode.
+  WritingMode mWM;
+
+  // The available size for children. The inline-size is stationary after the
+  // constructor, but the block-size will be adjusted as we reflow children.
+  LogicalSize mAvailSize;
+};
+
+struct TableBCData final {
+  TableArea mDamageArea;
+  BCPixelSize mBStartBorderWidth = 0;
+  BCPixelSize mIEndBorderWidth = 0;
+  BCPixelSize mBEndBorderWidth = 0;
+  BCPixelSize mIStartBorderWidth = 0;
+  BCPixelSize mIStartCellBorderWidth = 0;
+  BCPixelSize mIEndCellBorderWidth = 0;
+};
+
+}  // namespace mozilla
+
+/********************************************************************************
+ ** nsTableFrame **
+ ********************************************************************************/
+
+ComputedStyle* nsTableFrame::GetParentComputedStyle(
+    nsIFrame** aProviderFrame) const {
+  // Since our parent, the table wrapper frame, returned this frame, we
+  // must return whatever our parent would normally have returned.
+
+  MOZ_ASSERT(GetParent(), "table constructed without table wrapper");
+  if (!mContent->GetParent() && !Style()->IsPseudoOrAnonBox()) {
+    // We're the root.  We have no ComputedStyle parent.
+    *aProviderFrame = nullptr;
+    return nullptr;
+  }
+
+  return GetParent()->DoGetParentComputedStyle(aProviderFrame);
+}
+
+nsTableFrame::nsTableFrame(ComputedStyle* aStyle, nsPresContext* aPresContext,
+                           ClassID aID)
+    : nsContainerFrame(aStyle, aPresContext, aID) {
+  memset(&mBits, 0, sizeof(mBits));
+}
+
+void nsTableFrame::Init(nsIContent* aContent, nsContainerFrame* aParent,
+                        nsIFrame* aPrevInFlow) {
+  MOZ_ASSERT(!mCellMap, "Init called twice");
+  MOZ_ASSERT(!mTableLayoutStrategy, "Init called twice");
+  MOZ_ASSERT(!aPrevInFlow || aPrevInFlow->IsTableFrame(),
+             "prev-in-flow must be of same type");
+
+  // Let the base class do its processing
+  nsContainerFrame::Init(aContent, aParent, aPrevInFlow);
+
+  // see if border collapse is on, if so set it
+  const nsStyleTableBorder* tableStyle = StyleTableBorder();
+  bool borderCollapse =
+      (StyleBorderCollapse::Collapse == tableStyle->mBorderCollapse);
+  SetBorderCollapse(borderCollapse);
+  if (borderCollapse) {
+    SetNeedToCalcHasBCBorders(true);
+  }
+
+  if (!aPrevInFlow) {
+    // If we're the first-in-flow, we manage the cell map & layout strategy that
+    // get used by our continuation chain:
+    mCellMap = MakeUnique<nsTableCellMap>(*this, borderCollapse);
+    if (IsAutoLayout()) {
+      mTableLayoutStrategy = MakeUnique<BasicTableLayoutStrategy>(this);
+    } else {
+      mTableLayoutStrategy = MakeUnique<FixedTableLayoutStrategy>(this);
+    }
+  } else {
+    // Set my isize, because all frames in a table flow are the same isize and
+    // code in nsTableWrapperFrame depends on this being set.
+    WritingMode wm = GetWritingMode();
+    SetSize(LogicalSize(wm, aPrevInFlow->ISize(wm), BSize(wm)));
+  }
+}
+
+// Define here (Rather than in the header), even if it's trival, to avoid
+// UniquePtr members causing compile errors when their destructors are
+// implicitly inserted into this destructor. Destruction requires
+// the full definition of types that these UniquePtrs are managing, and
+// the header only has forward declarations of them.
+nsTableFrame::~nsTableFrame() = default;
+
+void nsTableFrame::Destroy(DestroyContext& aContext) {
+  MOZ_ASSERT(!mBits.mIsDestroying);
+  mBits.mIsDestroying = true;
+  mColGroups.DestroyFrames(aContext);
+  nsContainerFrame::Destroy(aContext);
+}
+
+// Make sure any views are positioned properly
+void nsTableFrame::RePositionViews(nsIFrame* aFrame) {
+  nsContainerFrame::PositionFrameView(aFrame);
+  nsContainerFrame::PositionChildViews(aFrame);
+}
+
+static bool IsRepeatedFrame(nsIFrame* kidFrame) {
+  return (kidFrame->IsTableRowFrame() || kidFrame->IsTableRowGroupFrame()) &&
+         kidFrame->HasAnyStateBits(NS_REPEATED_ROW_OR_ROWGROUP);
+}
+
+bool nsTableFrame::PageBreakAfter(nsIFrame* aSourceFrame,
+                                  nsIFrame* aNextFrame) {
+  const nsStyleDisplay* display = aSourceFrame->StyleDisplay();
+  nsTableRowGroupFrame* prevRg = do_QueryFrame(aSourceFrame);
+  // don't allow a page break after a repeated element ...
+  if ((display->BreakAfter() || (prevRg && prevRg->HasInternalBreakAfter())) &&
+      !IsRepeatedFrame(aSourceFrame)) {
+    return !(aNextFrame && IsRepeatedFrame(aNextFrame));  // or before
+  }
+
+  if (aNextFrame) {
+    display = aNextFrame->StyleDisplay();
+    // don't allow a page break before a repeated element ...
+    nsTableRowGroupFrame* nextRg = do_QueryFrame(aNextFrame);
+    if ((display->BreakBefore() ||
+         (nextRg && nextRg->HasInternalBreakBefore())) &&
+        !IsRepeatedFrame(aNextFrame)) {
+      return !IsRepeatedFrame(aSourceFrame);  // or after
+    }
+  }
+  return false;
+}
+
+/* static */
+void nsTableFrame::PositionedTablePartMaybeChanged(nsIFrame* aFrame,
+                                                   ComputedStyle* aOldStyle) {
+  const bool wasPositioned =
+      aOldStyle && aOldStyle->IsAbsPosContainingBlock(aFrame);
+  const bool isPositioned = aFrame->IsAbsPosContainingBlock();
+  MOZ_ASSERT(isPositioned == aFrame->Style()->IsAbsPosContainingBlock(aFrame));
+  if (wasPositioned == isPositioned) {
+    return;
+  }
+
+  nsTableFrame* tableFrame = GetTableFrame(aFrame);
+  MOZ_ASSERT(tableFrame, "Should have a table frame here");
+  tableFrame = static_cast<nsTableFrame*>(tableFrame->FirstContinuation());
+
+  // Retrieve the positioned parts array for this table.
+  FrameTArray* positionedParts =
+      tableFrame->GetProperty(PositionedTablePartArray());
+
+  // Lazily create the array if it doesn't exist yet.
+  if (!positionedParts) {
+    positionedParts = new FrameTArray;
+    tableFrame->SetProperty(PositionedTablePartArray(), positionedParts);
+  }
+
+  if (isPositioned) {
+    // Add this frame to the list.
+    positionedParts->AppendElement(aFrame);
+  } else {
+    positionedParts->RemoveElement(aFrame);
+  }
+}
+
+/* static */
+void nsTableFrame::MaybeUnregisterPositionedTablePart(nsIFrame* aFrame) {
+  if (!aFrame->IsAbsPosContainingBlock()) {
+    return;
+  }
+  nsTableFrame* tableFrame = GetTableFrame(aFrame);
+  tableFrame = static_cast<nsTableFrame*>(tableFrame->FirstContinuation());
+
+  if (tableFrame->IsDestroying()) {
+    return;  // We're throwing the table away anyways.
+  }
+
+  // Retrieve the positioned parts array for this table.
+  FrameTArray* positionedParts =
+      tableFrame->GetProperty(PositionedTablePartArray());
+
+  // Remove the frame.
+  MOZ_ASSERT(
+      positionedParts && positionedParts->Contains(aFrame),
+      "Asked to unregister a positioned table part that wasn't registered");
+  if (positionedParts) {
+    positionedParts->RemoveElement(aFrame);
+  }
+}
+
+// XXX this needs to be cleaned up so that the frame constructor breaks out col
+// group frames into a separate child list, bug 343048.
+void nsTableFrame::SetInitialChildList(ChildListID aListID,
+                                       nsFrameList&& aChildList) {
+  if (aListID != FrameChildListID::Principal) {
+    nsContainerFrame::SetInitialChildList(aListID, std::move(aChildList));
+    return;
+  }
+
+  MOZ_ASSERT(mFrames.IsEmpty() && mColGroups.IsEmpty(),
+             "unexpected second call to SetInitialChildList");
+#ifdef DEBUG
+  for (nsIFrame* f : aChildList) {
+    MOZ_ASSERT(f->GetParent() == this, "Unexpected parent");
+  }
+#endif
+
+  // XXXbz the below code is an icky cesspit that's only needed in its current
+  // form for two reasons:
+  // 1) Both rowgroups and column groups come in on the principal child list.
+  while (aChildList.NotEmpty()) {
+    nsIFrame* childFrame = aChildList.FirstChild();
+    aChildList.RemoveFirstChild();
+    const nsStyleDisplay* childDisplay = childFrame->StyleDisplay();
+
+    if (mozilla::StyleDisplay::TableColumnGroup == childDisplay->mDisplay) {
+      NS_ASSERTION(childFrame->IsTableColGroupFrame(),
+                   "This is not a colgroup");
+      mColGroups.AppendFrame(nullptr, childFrame);
+    } else {  // row groups and unknown frames go on the main list for now
+      mFrames.AppendFrame(nullptr, childFrame);
+    }
+  }
+
+  // If we have a prev-in-flow, then we're a table that has been split and
+  // so don't treat this like an append
+  if (!GetPrevInFlow()) {
+    // process col groups first so that real cols get constructed before
+    // anonymous ones due to cells in rows.
+    InsertColGroups(0, mColGroups);
+    InsertRowGroups(mFrames);
+    // calc collapsing borders
+    if (IsBorderCollapse()) {
+      SetFullBCDamageArea();
+    }
+  }
+}
+
+void nsTableFrame::RowOrColSpanChanged(nsTableCellFrame* aCellFrame) {
+  if (aCellFrame) {
+    nsTableCellMap* cellMap = GetCellMap();
+    if (cellMap) {
+      // for now just remove the cell from the map and reinsert it
+      uint32_t rowIndex = aCellFrame->RowIndex();
+      uint32_t colIndex = aCellFrame->ColIndex();
+      RemoveCell(aCellFrame, rowIndex);
+      AutoTArray<nsTableCellFrame*, 1> cells;
+      cells.AppendElement(aCellFrame);
+      InsertCells(cells, rowIndex, colIndex - 1);
+
+      // XXX Should this use IntrinsicDirty::FrameAncestorsAndDescendants? It
+      // currently doesn't need to, but it might given more optimization.
+      PresShell()->FrameNeedsReflow(this, IntrinsicDirty::FrameAndAncestors,
+                                    NS_FRAME_IS_DIRTY);
+    }
+  }
+}
+
+/* ****** CellMap methods ******* */
+
+/* return the effective col count */
+int32_t nsTableFrame::GetEffectiveColCount() const {
+  int32_t colCount = GetColCount();
+  if (LayoutStrategy()->GetType() == nsITableLayoutStrategy::Auto) {
+    nsTableCellMap* cellMap = GetCellMap();
+    if (!cellMap) {
+      return 0;
+    }
+    // don't count cols at the end that don't have originating cells
+    for (int32_t colIdx = colCount - 1; colIdx >= 0; colIdx--) {
+      if (cellMap->GetNumCellsOriginatingInCol(colIdx) > 0) {
+        break;
+      }
+      colCount--;
+    }
+  }
+  return colCount;
+}
+
+int32_t nsTableFrame::GetIndexOfLastRealCol() {
+  int32_t numCols = mColFrames.Length();
+  if (numCols > 0) {
+    for (int32_t colIdx = numCols - 1; colIdx >= 0; colIdx--) {
+      nsTableColFrame* colFrame = GetColFrame(colIdx);
+      if (colFrame) {
+        if (eColAnonymousCell != colFrame->GetColType()) {
+          return colIdx;
+        }
+      }
+    }
+  }
+  return -1;
+}
+
+nsTableColFrame* nsTableFrame::GetColFrame(int32_t aColIndex) const {
+  MOZ_ASSERT(!GetPrevInFlow(), "GetColFrame called on next in flow");
+  int32_t numCols = mColFrames.Length();
+  if ((aColIndex >= 0) && (aColIndex < numCols)) {
+    MOZ_ASSERT(mColFrames.ElementAt(aColIndex));
+    return mColFrames.ElementAt(aColIndex);
+  } else {
+    MOZ_ASSERT_UNREACHABLE("invalid col index");
+    return nullptr;
+  }
+}
+
+int32_t nsTableFrame::GetEffectiveRowSpan(int32_t aRowIndex,
+                                          const nsTableCellFrame& aCell) const {
+  nsTableCellMap* cellMap = GetCellMap();
+  MOZ_ASSERT(nullptr != cellMap, "bad call, cellMap not yet allocated.");
+
+  return cellMap->GetEffectiveRowSpan(aRowIndex, aCell.ColIndex());
+}
+
+int32_t nsTableFrame::GetEffectiveRowSpan(const nsTableCellFrame& aCell,
+                                          nsCellMap* aCellMap) {
+  nsTableCellMap* tableCellMap = GetCellMap();
+  if (!tableCellMap) ABORT1(1);
+
+  uint32_t colIndex = aCell.ColIndex();
+  uint32_t rowIndex = aCell.RowIndex();
+
+  if (aCellMap)
+    return aCellMap->GetRowSpan(rowIndex, colIndex, true);
+  else
+    return tableCellMap->GetEffectiveRowSpan(rowIndex, colIndex);
+}
+
+int32_t nsTableFrame::GetEffectiveColSpan(const nsTableCellFrame& aCell,
+                                          nsCellMap* aCellMap) const {
+  nsTableCellMap* tableCellMap = GetCellMap();
+  if (!tableCellMap) ABORT1(1);
+
+  uint32_t colIndex = aCell.ColIndex();
+  uint32_t rowIndex = aCell.RowIndex();
+
+  if (aCellMap)
+    return aCellMap->GetEffectiveColSpan(*tableCellMap, rowIndex, colIndex);
+  else
+    return tableCellMap->GetEffectiveColSpan(rowIndex, colIndex);
+}
+
+bool nsTableFrame::HasMoreThanOneCell(int32_t aRowIndex) const {
+  nsTableCellMap* tableCellMap = GetCellMap();
+  if (!tableCellMap) ABORT1(1);
+  return tableCellMap->HasMoreThanOneCell(aRowIndex);
+}
+
+void nsTableFrame::AdjustRowIndices(int32_t aRowIndex, int32_t aAdjustment) {
+  // Iterate over the row groups and adjust the row indices of all rows
+  // whose index is >= aRowIndex.
+  RowGroupArray rowGroups = OrderedRowGroups();
+
+  for (uint32_t rgIdx = 0; rgIdx < rowGroups.Length(); rgIdx++) {
+    rowGroups[rgIdx]->AdjustRowIndices(aRowIndex, aAdjustment);
+  }
+}
+
+void nsTableFrame::ResetRowIndices(
+    const nsFrameList::Slice& aRowGroupsToExclude) {
+  // Iterate over the row groups and adjust the row indices of all rows
+  // omit the rowgroups that will be inserted later
+  mDeletedRowIndexRanges.clear();
+
+  RowGroupArray rowGroups = OrderedRowGroups();
+
+  nsTHashSet<nsTableRowGroupFrame*> excludeRowGroups;
+  for (nsIFrame* excludeRowGroup : aRowGroupsToExclude) {
+    excludeRowGroups.Insert(
+        static_cast<nsTableRowGroupFrame*>(excludeRowGroup));
+#ifdef DEBUG
+    {
+      // Check to make sure that the row indices of all rows in excluded row
+      // groups are '0' (i.e. the initial value since they haven't been added
+      // yet)
+      const nsFrameList& rowFrames = excludeRowGroup->PrincipalChildList();
+      for (nsIFrame* r : rowFrames) {
+        auto* row = static_cast<nsTableRowFrame*>(r);
+        MOZ_ASSERT(row->GetRowIndex() == 0,
+                   "exclusions cannot be used for rows that were already added,"
+                   "because we'd need to process mDeletedRowIndexRanges");
+      }
+    }
+#endif
+  }
+
+  int32_t rowIndex = 0;
+  for (uint32_t rgIdx = 0; rgIdx < rowGroups.Length(); rgIdx++) {
+    nsTableRowGroupFrame* rgFrame = rowGroups[rgIdx];
+    if (!excludeRowGroups.Contains(rgFrame)) {
+      const nsFrameList& rowFrames = rgFrame->PrincipalChildList();
+      for (nsIFrame* r : rowFrames) {
+        if (mozilla::StyleDisplay::TableRow == r->StyleDisplay()->mDisplay) {
+          auto* row = static_cast<nsTableRowFrame*>(r);
+          row->SetRowIndex(rowIndex);
+          rowIndex++;
+        }
+      }
+    }
+  }
+}
+
+void nsTableFrame::InsertColGroups(int32_t aStartColIndex,
+                                   const nsFrameList::Slice& aColGroups) {
+  int32_t colIndex = aStartColIndex;
+
+  // XXX: We cannot use range-based for loop because AddColsToTable() can
+  // destroy the nsTableColGroupFrame in the slice we're traversing! Need to
+  // check the validity of *colGroupIter.
+  auto colGroupIter = aColGroups.begin();
+  for (auto colGroupIterEnd = aColGroups.end();
+       *colGroupIter && colGroupIter != colGroupIterEnd; ++colGroupIter) {
+    MOZ_ASSERT((*colGroupIter)->IsTableColGroupFrame());
+    auto* cgFrame = static_cast<nsTableColGroupFrame*>(*colGroupIter);
+    cgFrame->SetStartColumnIndex(colIndex);
+    cgFrame->AddColsToTable(colIndex, false, cgFrame->PrincipalChildList());
+    int32_t numCols = cgFrame->GetColCount();
+    colIndex += numCols;
+  }
+
+  if (*colGroupIter) {
+    nsTableColGroupFrame::ResetColIndices(*colGroupIter, colIndex);
+  }
+}
+
+void nsTableFrame::InsertCol(nsTableColFrame& aColFrame, int32_t aColIndex) {
+  mColFrames.InsertElementAt(aColIndex, &aColFrame);
+  nsTableColType insertedColType = aColFrame.GetColType();
+  int32_t numCacheCols = mColFrames.Length();
+  nsTableCellMap* cellMap = GetCellMap();
+  if (cellMap) {
+    int32_t numMapCols = cellMap->GetColCount();
+    if (numCacheCols > numMapCols) {
+      bool removedFromCache = false;
+      if (eColAnonymousCell != insertedColType) {
+        nsTableColFrame* lastCol = mColFrames.ElementAt(numCacheCols - 1);
+        if (lastCol) {
+          nsTableColType lastColType = lastCol->GetColType();
+          if (eColAnonymousCell == lastColType) {
+            // remove the col from the cache
+            mColFrames.RemoveLastElement();
+            // remove the col from the synthetic col group
+            nsTableColGroupFrame* lastColGroup =
+                (nsTableColGroupFrame*)mColGroups.LastChild();
+            if (lastColGroup) {
+              MOZ_ASSERT(lastColGroup->IsSynthetic());
+              DestroyContext context(PresShell());
+              lastColGroup->RemoveChild(context, *lastCol, false);
+
+              // remove the col group if it is empty
+              if (lastColGroup->GetColCount() <= 0) {
+                mColGroups.DestroyFrame(context, (nsIFrame*)lastColGroup);
+              }
+            }
+            removedFromCache = true;
+          }
+        }
+      }
+      if (!removedFromCache) {
+        cellMap->AddColsAtEnd(1);
+      }
+    }
+  }
+  // for now, just bail and recalc all of the collapsing borders
+  if (IsBorderCollapse()) {
+    TableArea damageArea(aColIndex, 0, GetColCount() - aColIndex,
+                         GetRowCount());
+    AddBCDamageArea(damageArea);
+  }
+}
+
+void nsTableFrame::RemoveCol(nsTableColGroupFrame* aColGroupFrame,
+                             int32_t aColIndex, bool aRemoveFromCache,
+                             bool aRemoveFromCellMap) {
+  if (aRemoveFromCache) {
+    mColFrames.RemoveElementAt(aColIndex);
+  }
+  if (aRemoveFromCellMap) {
+    nsTableCellMap* cellMap = GetCellMap();
+    if (cellMap) {
+      // If we have some anonymous cols at the end already, we just
+      // add a new anonymous col.
+      if (!mColFrames.IsEmpty() &&
+          mColFrames.LastElement() &&  // XXXbz is this ever null?
+          mColFrames.LastElement()->GetColType() == eColAnonymousCell) {
+        AppendAnonymousColFrames(1);
+      } else {
+        // All of our colframes correspond to actual <col> tags.  It's possible
+        // that we still have at least as many <col> tags as we have logical
+        // columns from cells, but we might have one less.  Handle the latter
+        // case as follows: First ask the cellmap to drop its last col if it
+        // doesn't have any actual cells in it.  Then call
+        // MatchCellMapToColCache to append an anonymous column if it's needed;
+        // this needs to be after RemoveColsAtEnd, since it will determine the
+        // need for a new column frame based on the width of the cell map.
+        cellMap->RemoveColsAtEnd();
+        MatchCellMapToColCache(cellMap);
+      }
+    }
+  }
+  // for now, just bail and recalc all of the collapsing borders
+  if (IsBorderCollapse()) {
+    TableArea damageArea(0, 0, GetColCount(), GetRowCount());
+    AddBCDamageArea(damageArea);
+  }
+}
+
+/** Get the cell map for this table frame.  It is not always mCellMap.
+ * Only the first-in-flow has a legit cell map.
+ */
+nsTableCellMap* nsTableFrame::GetCellMap() const {
+  return static_cast<nsTableFrame*>(FirstInFlow())->mCellMap.get();
+}
+
+nsTableColGroupFrame* nsTableFrame::CreateSyntheticColGroupFrame() {
+  nsIContent* colGroupContent = GetContent();
+  mozilla::PresShell* presShell = PresShell();
+
+  RefPtr<ComputedStyle> colGroupStyle;
+  colGroupStyle = presShell->StyleSet()->ResolveNonInheritingAnonymousBoxStyle(
+      PseudoStyleType::tableColGroup);
+  // Create a col group frame
+  nsTableColGroupFrame* newFrame =
+      NS_NewTableColGroupFrame(presShell, colGroupStyle);
+  newFrame->SetIsSynthetic();
+  newFrame->Init(colGroupContent, this, nullptr);
+  return newFrame;
+}
+
+void nsTableFrame::AppendAnonymousColFrames(int32_t aNumColsToAdd) {
+  MOZ_ASSERT(aNumColsToAdd > 0, "We should be adding _something_.");
+  // get the last col group frame
+  nsTableColGroupFrame* colGroupFrame =
+      static_cast<nsTableColGroupFrame*>(mColGroups.LastChild());
+
+  if (!colGroupFrame || !colGroupFrame->IsSynthetic()) {
+    int32_t colIndex = (colGroupFrame) ? colGroupFrame->GetStartColumnIndex() +
+                                             colGroupFrame->GetColCount()
+                                       : 0;
+    colGroupFrame = CreateSyntheticColGroupFrame();
+    if (!colGroupFrame) {
+      return;
+    }
+    // add the new frame to the child list
+    mColGroups.AppendFrame(this, colGroupFrame);
+    colGroupFrame->SetStartColumnIndex(colIndex);
+  }
+  AppendAnonymousColFrames(colGroupFrame, aNumColsToAdd, eColAnonymousCell,
+                           true);
+}
+
+// XXX this needs to be moved to nsCSSFrameConstructor
+// Right now it only creates the col frames at the end
+void nsTableFrame::AppendAnonymousColFrames(
+    nsTableColGroupFrame* aColGroupFrame, int32_t aNumColsToAdd,
+    nsTableColType aColType, bool aAddToTable) {
+  MOZ_ASSERT(aColGroupFrame, "null frame");
+  MOZ_ASSERT(aColType != eColAnonymousCol, "Shouldn't happen");
+  MOZ_ASSERT(aNumColsToAdd > 0, "We should be adding _something_.");
+
+  mozilla::PresShell* presShell = PresShell();
+
+  // Get the last col frame
+  nsFrameList newColFrames;
+
+  int32_t startIndex = mColFrames.Length();
+  int32_t lastIndex = startIndex + aNumColsToAdd - 1;
+
+  for (int32_t childX = startIndex; childX <= lastIndex; childX++) {
+    // all anonymous cols that we create here use a pseudo ComputedStyle of the
+    // col group
+    nsIContent* iContent = aColGroupFrame->GetContent();
+    RefPtr<ComputedStyle> computedStyle =
+        presShell->StyleSet()->ResolveNonInheritingAnonymousBoxStyle(
+            PseudoStyleType::tableCol);
+    // ASSERTION to check for bug 54454 sneaking back in...
+    NS_ASSERTION(iContent, "null content in CreateAnonymousColFrames");
+
+    // create the new col frame
+    nsIFrame* colFrame = NS_NewTableColFrame(presShell, computedStyle);
+    ((nsTableColFrame*)colFrame)->SetColType(aColType);
+    colFrame->Init(iContent, aColGroupFrame, nullptr);
+
+    newColFrames.AppendFrame(nullptr, colFrame);
+  }
+  nsFrameList& cols = aColGroupFrame->GetWritableChildList();
+  nsIFrame* oldLastCol = cols.LastChild();
+  const nsFrameList::Slice& newCols =
+      cols.InsertFrames(nullptr, oldLastCol, std::move(newColFrames));
+  if (aAddToTable) {
+    // get the starting col index in the cache
+    int32_t startColIndex;
+    if (oldLastCol) {
+      startColIndex =
+          static_cast<nsTableColFrame*>(oldLastCol)->GetColIndex() + 1;
+    } else {
+      startColIndex = aColGroupFrame->GetStartColumnIndex();
+    }
+
+    aColGroupFrame->AddColsToTable(startColIndex, true, newCols);
+  }
+}
+
+void nsTableFrame::MatchCellMapToColCache(nsTableCellMap* aCellMap) {
+  int32_t numColsInMap = GetColCount();
+  int32_t numColsInCache = mColFrames.Length();
+  int32_t numColsToAdd = numColsInMap - numColsInCache;
+  if (numColsToAdd > 0) {
+    // this sets the child list, updates the col cache and cell map
+    AppendAnonymousColFrames(numColsToAdd);
+  }
+  if (numColsToAdd < 0) {
+    int32_t numColsNotRemoved = DestroyAnonymousColFrames(-numColsToAdd);
+    // if the cell map has fewer cols than the cache, correct it
+    if (numColsNotRemoved > 0) {
+      aCellMap->AddColsAtEnd(numColsNotRemoved);
+    }
+  }
+}
+
+void nsTableFrame::DidResizeColumns() {
+  MOZ_ASSERT(!GetPrevInFlow(), "should only be called on first-in-flow");
+
+  if (mBits.mResizedColumns) return;  // already marked
+
+  for (nsTableFrame* f = this; f;
+       f = static_cast<nsTableFrame*>(f->GetNextInFlow()))
+    f->mBits.mResizedColumns = true;
+}
+
+void nsTableFrame::AppendCell(nsTableCellFrame& aCellFrame, int32_t aRowIndex) {
+  nsTableCellMap* cellMap = GetCellMap();
+  if (cellMap) {
+    TableArea damageArea(0, 0, 0, 0);
+    cellMap->AppendCell(aCellFrame, aRowIndex, true, damageArea);
+    MatchCellMapToColCache(cellMap);
+    if (IsBorderCollapse()) {
+      AddBCDamageArea(damageArea);
+    }
+  }
+}
+
+void nsTableFrame::InsertCells(nsTArray<nsTableCellFrame*>& aCellFrames,
+                               int32_t aRowIndex, int32_t aColIndexBefore) {
+  nsTableCellMap* cellMap = GetCellMap();
+  if (cellMap) {
+    TableArea damageArea(0, 0, 0, 0);
+    cellMap->InsertCells(aCellFrames, aRowIndex, aColIndexBefore, damageArea);
+    MatchCellMapToColCache(cellMap);
+    if (IsBorderCollapse()) {
+      AddBCDamageArea(damageArea);
+    }
+  }
+}
+
+// this removes the frames from the col group and table, but not the cell map
+int32_t nsTableFrame::DestroyAnonymousColFrames(int32_t aNumFrames) {
+  // only remove cols that are of type eTypeAnonymous cell (they are at the end)
+  int32_t endIndex = mColFrames.Length() - 1;
+  int32_t startIndex = (endIndex - aNumFrames) + 1;
+  int32_t numColsRemoved = 0;
+  DestroyContext context(PresShell());
+  for (int32_t colIdx = endIndex; colIdx >= startIndex; colIdx--) {
+    nsTableColFrame* colFrame = GetColFrame(colIdx);
+    if (colFrame && (eColAnonymousCell == colFrame->GetColType())) {
+      auto* cgFrame = static_cast<nsTableColGroupFrame*>(colFrame->GetParent());
+      // remove the frame from the colgroup
+      cgFrame->RemoveChild(context, *colFrame, false);
+      // remove the frame from the cache, but not the cell map
+      RemoveCol(nullptr, colIdx, true, false);
+      numColsRemoved++;
+    } else {
+      break;
+    }
+  }
+  return (aNumFrames - numColsRemoved);
+}
+
+void nsTableFrame::RemoveCell(nsTableCellFrame* aCellFrame, int32_t aRowIndex) {
+  nsTableCellMap* cellMap = GetCellMap();
+  if (cellMap) {
+    TableArea damageArea(0, 0, 0, 0);
+    cellMap->RemoveCell(aCellFrame, aRowIndex, damageArea);
+    MatchCellMapToColCache(cellMap);
+    if (IsBorderCollapse()) {
+      AddBCDamageArea(damageArea);
+    }
+  }
+}
+
+int32_t nsTableFrame::GetStartRowIndex(
+    const nsTableRowGroupFrame* aRowGroupFrame) const {
+  RowGroupArray orderedRowGroups = OrderedRowGroups();
+
+  int32_t rowIndex = 0;
+  for (uint32_t rgIndex = 0; rgIndex < orderedRowGroups.Length(); rgIndex++) {
+    nsTableRowGroupFrame* rgFrame = orderedRowGroups[rgIndex];
+    if (rgFrame == aRowGroupFrame) {
+      break;
+    }
+    int32_t numRows = rgFrame->GetRowCount();
+    rowIndex += numRows;
+  }
+  return rowIndex;
+}
+
+// this cannot extend beyond a single row group
+void nsTableFrame::AppendRows(nsTableRowGroupFrame* aRowGroupFrame,
+                              int32_t aRowIndex,
+                              nsTArray<nsTableRowFrame*>& aRowFrames) {
+  nsTableCellMap* cellMap = GetCellMap();
+  if (cellMap) {
+    int32_t absRowIndex = GetStartRowIndex(aRowGroupFrame) + aRowIndex;
+    InsertRows(aRowGroupFrame, aRowFrames, absRowIndex, true);
+  }
+}
+
+// this cannot extend beyond a single row group
+int32_t nsTableFrame::InsertRows(nsTableRowGroupFrame* aRowGroupFrame,
+                                 nsTArray<nsTableRowFrame*>& aRowFrames,
+                                 int32_t aRowIndex, bool aConsiderSpans) {
+#ifdef DEBUG_TABLE_CELLMAP
+  printf("=== insertRowsBefore firstRow=%d \n", aRowIndex);
+  Dump(true, false, true);
+#endif
+
+  int32_t numColsToAdd = 0;
+  nsTableCellMap* cellMap = GetCellMap();
+  if (cellMap) {
+    TableArea damageArea(0, 0, 0, 0);
+    bool shouldRecalculateIndex = !IsDeletedRowIndexRangesEmpty();
+    if (shouldRecalculateIndex) {
+      ResetRowIndices(nsFrameList::Slice(nullptr, nullptr));
+    }
+    int32_t origNumRows = cellMap->GetRowCount();
+    int32_t numNewRows = aRowFrames.Length();
+    cellMap->InsertRows(aRowGroupFrame, aRowFrames, aRowIndex, aConsiderSpans,
+                        damageArea);
+    MatchCellMapToColCache(cellMap);
+
+    // Perform row index adjustment only if row indices were not
+    // reset above
+    if (!shouldRecalculateIndex) {
+      if (aRowIndex < origNumRows) {
+        AdjustRowIndices(aRowIndex, numNewRows);
+      }
+
+      // assign the correct row indices to the new rows. If they were
+      // recalculated above it may not have been done correctly because each row
+      // is constructed with index 0
+      for (int32_t rowB = 0; rowB < numNewRows; rowB++) {
+        nsTableRowFrame* rowFrame = aRowFrames.ElementAt(rowB);
+        rowFrame->SetRowIndex(aRowIndex + rowB);
+      }
+    }
+
+    if (IsBorderCollapse()) {
+      AddBCDamageArea(damageArea);
+    }
+  }
+#ifdef DEBUG_TABLE_CELLMAP
+  printf("=== insertRowsAfter \n");
+  Dump(true, false, true);
+#endif
+
+  return numColsToAdd;
+}
+
+void nsTableFrame::AddDeletedRowIndex(int32_t aDeletedRowStoredIndex) {
+  if (mDeletedRowIndexRanges.empty()) {
+    mDeletedRowIndexRanges.insert(std::pair<int32_t, int32_t>(
+        aDeletedRowStoredIndex, aDeletedRowStoredIndex));
+    return;
+  }
+
+  // Find the position of the current deleted row's stored index
+  // among the previous deleted row index ranges and merge ranges if
+  // they are consecutive, else add a new (disjoint) range to the map.
+  // Call to mDeletedRowIndexRanges.upper_bound is
+  // O(log(mDeletedRowIndexRanges.size())) therefore call to
+  // AddDeletedRowIndex is also ~O(log(mDeletedRowIndexRanges.size()))
+
+  // greaterIter = will point to smallest range in the map with lower value
+  //              greater than the aDeletedRowStoredIndex.
+  //              If no such value exists, point to end of map.
+  // smallerIter = will point to largest range in the map with higher value
+  //              smaller than the aDeletedRowStoredIndex
+  //              If no such value exists, point to beginning of map.
+  // i.e. when both values exist below is true:
+  // smallerIter->second < aDeletedRowStoredIndex < greaterIter->first
+  auto greaterIter = mDeletedRowIndexRanges.upper_bound(aDeletedRowStoredIndex);
+  auto smallerIter = greaterIter;
+
+  if (smallerIter != mDeletedRowIndexRanges.begin()) {
+    smallerIter--;
+    // While greaterIter might be out-of-bounds (by being equal to end()),
+    // smallerIter now cannot be, since we returned early above for a 0-size
+    // map.
+  }
+
+  // Note: smallerIter can only be equal to greaterIter when both
+  // of them point to the beginning of the map and in that case smallerIter
+  // does not "exist" but we clip smallerIter to point to beginning of map
+  // so that it doesn't point to something unknown or outside the map boundry.
+  // Note: When greaterIter is not the end (i.e. it "exists") upper_bound()
+  // ensures aDeletedRowStoredIndex < greaterIter->first so no need to
+  // assert that.
+  MOZ_ASSERT(smallerIter == greaterIter ||
+                 aDeletedRowStoredIndex > smallerIter->second,
+             "aDeletedRowIndexRanges already contains aDeletedRowStoredIndex! "
+             "Trying to delete an already deleted row?");
+
+  if (smallerIter->second == aDeletedRowStoredIndex - 1) {
+    if (greaterIter != mDeletedRowIndexRanges.end() &&
+        greaterIter->first == aDeletedRowStoredIndex + 1) {
+      // merge current index with smaller and greater range as they are
+      // consecutive
+      smallerIter->second = greaterIter->second;
+      mDeletedRowIndexRanges.erase(greaterIter);
+    } else {
+      // add aDeletedRowStoredIndex in the smaller range as it is consecutive
+      smallerIter->second = aDeletedRowStoredIndex;
+    }
+  } else if (greaterIter != mDeletedRowIndexRanges.end() &&
+             greaterIter->first == aDeletedRowStoredIndex + 1) {
+    // add aDeletedRowStoredIndex in the greater range as it is consecutive
+    mDeletedRowIndexRanges.insert(std::pair<int32_t, int32_t>(
+        aDeletedRowStoredIndex, greaterIter->second));
+    mDeletedRowIndexRanges.erase(greaterIter);
+  } else {
+    // add new range as aDeletedRowStoredIndex is disjoint from existing ranges
+    mDeletedRowIndexRanges.insert(std::pair<int32_t, int32_t>(
+        aDeletedRowStoredIndex, aDeletedRowStoredIndex));
+  }
+}
+
+int32_t nsTableFrame::GetAdjustmentForStoredIndex(int32_t aStoredIndex) {
+  if (mDeletedRowIndexRanges.empty()) return 0;
+
+  int32_t adjustment = 0;
+
+  // O(log(mDeletedRowIndexRanges.size()))
+  auto endIter = mDeletedRowIndexRanges.upper_bound(aStoredIndex);
+  for (auto iter = mDeletedRowIndexRanges.begin(); iter != endIter; ++iter) {
+    adjustment += iter->second - iter->first + 1;
+  }
+
+  return adjustment;
+}
+
+// this cannot extend beyond a single row group
+void nsTableFrame::RemoveRows(nsTableRowFrame& aFirstRowFrame,
+                              int32_t aNumRowsToRemove, bool aConsiderSpans) {
+#ifdef TBD_OPTIMIZATION
+  // decide if we need to rebalance. we have to do this here because the row
+  // group cannot do it when it gets the dirty reflow corresponding to the frame
+  // being destroyed
+  bool stopTelling = false;
+  for (nsIFrame* kidFrame = aFirstFrame.FirstChild(); (kidFrame && !stopAsking);
+       kidFrame = kidFrame->GetNextSibling()) {
+    nsTableCellFrame* cellFrame = do_QueryFrame(kidFrame);
+    if (cellFrame) {
+      stopTelling = tableFrame->CellChangedWidth(
+          *cellFrame, cellFrame->GetPass1MaxElementWidth(),
+          cellFrame->GetMaximumWidth(), true);
+    }
+  }
+  // XXX need to consider what happens if there are cells that have rowspans
+  // into the deleted row. Need to consider moving rows if a rebalance doesn't
+  // happen
+#endif
+
+  int32_t firstRowIndex = aFirstRowFrame.GetRowIndex();
+#ifdef DEBUG_TABLE_CELLMAP
+  printf("=== removeRowsBefore firstRow=%d numRows=%d\n", firstRowIndex,
+         aNumRowsToRemove);
+  Dump(true, false, true);
+#endif
+  nsTableCellMap* cellMap = GetCellMap();
+  if (cellMap) {
+    TableArea damageArea(0, 0, 0, 0);
+
+    // Mark rows starting from aFirstRowFrame to the next 'aNumRowsToRemove-1'
+    // number of rows as deleted.
+    nsTableRowGroupFrame* parentFrame = aFirstRowFrame.GetTableRowGroupFrame();
+    parentFrame->MarkRowsAsDeleted(aFirstRowFrame, aNumRowsToRemove);
+
+    cellMap->RemoveRows(firstRowIndex, aNumRowsToRemove, aConsiderSpans,
+                        damageArea);
+    MatchCellMapToColCache(cellMap);
+    if (IsBorderCollapse()) {
+      AddBCDamageArea(damageArea);
+    }
+  }
+
+#ifdef DEBUG_TABLE_CELLMAP
+  printf("=== removeRowsAfter\n");
+  Dump(true, true, true);
+#endif
+}
+
+// collect the rows ancestors of aFrame
+int32_t nsTableFrame::CollectRows(nsIFrame* aFrame,
+                                  nsTArray<nsTableRowFrame*>& aCollection) {
+  MOZ_ASSERT(aFrame, "null frame");
+  int32_t numRows = 0;
+  for (nsIFrame* childFrame : aFrame->PrincipalChildList()) {
+    aCollection.AppendElement(static_cast<nsTableRowFrame*>(childFrame));
+    numRows++;
+  }
+  return numRows;
+}
+
+void nsTableFrame::InsertRowGroups(const nsFrameList::Slice& aRowGroups) {
+#ifdef DEBUG_TABLE_CELLMAP
+  printf("=== insertRowGroupsBefore\n");
+  Dump(true, false, true);
+#endif
+  nsTableCellMap* cellMap = GetCellMap();
+  if (cellMap) {
+    RowGroupArray orderedRowGroups = OrderedRowGroups();
+
+    AutoTArray<nsTableRowFrame*, 8> rows;
+    // Loop over the rowgroups and check if some of them are new, if they are
+    // insert cellmaps in the order that is predefined by OrderedRowGroups.
+    // XXXbz this code is O(N*M) where N is number of new rowgroups
+    // and M is number of rowgroups we have!
+    uint32_t rgIndex;
+    for (rgIndex = 0; rgIndex < orderedRowGroups.Length(); rgIndex++) {
+      for (nsIFrame* rowGroup : aRowGroups) {
+        if (orderedRowGroups[rgIndex] == rowGroup) {
+          nsTableRowGroupFrame* priorRG =
+              (0 == rgIndex) ? nullptr : orderedRowGroups[rgIndex - 1];
+          // create and add the cell map for the row group
+          cellMap->InsertGroupCellMap(orderedRowGroups[rgIndex], priorRG);
+
+          break;
+        }
+      }
+    }
+    cellMap->Synchronize(this);
+    ResetRowIndices(aRowGroups);
+
+    // now that the cellmaps are reordered too insert the rows
+    for (rgIndex = 0; rgIndex < orderedRowGroups.Length(); rgIndex++) {
+      for (nsIFrame* rowGroup : aRowGroups) {
+        if (orderedRowGroups[rgIndex] == rowGroup) {
+          nsTableRowGroupFrame* priorRG =
+              (0 == rgIndex) ? nullptr : orderedRowGroups[rgIndex - 1];
+          // collect the new row frames in an array and add them to the table
+          int32_t numRows = CollectRows(rowGroup, rows);
+          if (numRows > 0) {
+            int32_t rowIndex = 0;
+            if (priorRG) {
+              int32_t priorNumRows = priorRG->GetRowCount();
+              rowIndex = priorRG->GetStartRowIndex() + priorNumRows;
+            }
+            InsertRows(orderedRowGroups[rgIndex], rows, rowIndex, true);
+            rows.Clear();
+          }
+          break;
+        }
+      }
+    }
+  }
+#ifdef DEBUG_TABLE_CELLMAP
+  printf("=== insertRowGroupsAfter\n");
+  Dump(true, true, true);
+#endif
+}
+
+/////////////////////////////////////////////////////////////////////////////
+// Child frame enumeration
+
+const nsFrameList& nsTableFrame::GetChildList(ChildListID aListID) const {
+  if (aListID == FrameChildListID::ColGroup) {
+    return mColGroups;
+  }
+  return nsContainerFrame::GetChildList(aListID);
+}
+
+void nsTableFrame::GetChildLists(nsTArray<ChildList>* aLists) const {
+  nsContainerFrame::GetChildLists(aLists);
+  mColGroups.AppendIfNonempty(aLists, FrameChildListID::ColGroup);
+}
+
+static inline bool FrameHasBorder(nsIFrame* f) {
+  if (!f->StyleVisibility()->IsVisible()) {
+    return false;
+  }
+
+  return f->StyleBorder()->HasBorder();
+}
+
+void nsTableFrame::CalcHasBCBorders() {
+  if (!IsBorderCollapse()) {
+    SetHasBCBorders(false);
+    return;
+  }
+
+  if (FrameHasBorder(this)) {
+    SetHasBCBorders(true);
+    return;
+  }
+
+  // Check col and col group has borders.
+  for (nsIFrame* f : this->GetChildList(FrameChildListID::ColGroup)) {
+    if (FrameHasBorder(f)) {
+      SetHasBCBorders(true);
+      return;
+    }
+
+    nsTableColGroupFrame* colGroup = static_cast<nsTableColGroupFrame*>(f);
+    for (nsTableColFrame* col = colGroup->GetFirstColumn(); col;
+         col = col->GetNextCol()) {
+      if (FrameHasBorder(col)) {
+        SetHasBCBorders(true);
+        return;
+      }
+    }
+  }
+
+  // check row group, row and cell has borders.
+  RowGroupArray rowGroups = OrderedRowGroups();
+  for (nsTableRowGroupFrame* rowGroup : rowGroups) {
+    if (FrameHasBorder(rowGroup)) {
+      SetHasBCBorders(true);
+      return;
+    }
+
+    for (nsTableRowFrame* row = rowGroup->GetFirstRow(); row;
+         row = row->GetNextRow()) {
+      if (FrameHasBorder(row)) {
+        SetHasBCBorders(true);
+        return;
+      }
+
+      for (nsTableCellFrame* cell = row->GetFirstCell(); cell;
+           cell = cell->GetNextCell()) {
+        if (FrameHasBorder(cell)) {
+          SetHasBCBorders(true);
+          return;
+        }
+      }
+    }
+  }
+
+  SetHasBCBorders(false);
+}
+
+namespace mozilla {
+class nsDisplayTableBorderCollapse;
+}
+
+// table paint code is concerned primarily with borders and bg color
+// SEC: TODO: adjust the rect for captions
+void nsTableFrame::BuildDisplayList(nsDisplayListBuilder* aBuilder,
+                                    const nsDisplayListSet& aLists) {
+  DO_GLOBAL_REFLOW_COUNT_DSP_COLOR("nsTableFrame", NS_RGB(255, 128, 255));
+
+  DisplayBorderBackgroundOutline(aBuilder, aLists);
+
+  nsDisplayTableBackgroundSet tableBGs(aBuilder, this);
+  nsDisplayListCollection lists(aBuilder);
+
+  // This is similar to what
+  // nsContainerFrame::BuildDisplayListForNonBlockChildren does, except that we
+  // allow the children's background and borders to go in our BorderBackground
+  // list. This doesn't really affect background painting --- the children won't
+  // actually draw their own backgrounds because the nsTableFrame already drew
+  // them, unless a child has its own stacking context, in which case the child
+  // won't use its passed-in BorderBackground list anyway. It does affect cell
+  // borders though; this lets us get cell borders into the nsTableFrame's
+  // BorderBackground list.
+  for (nsIFrame* colGroup :
+       FirstContinuation()->GetChildList(FrameChildListID::ColGroup)) {
+    for (nsIFrame* col : colGroup->PrincipalChildList()) {
+      tableBGs.AddColumn((nsTableColFrame*)col);
+    }
+  }
+
+  for (nsIFrame* kid : PrincipalChildList()) {
+    BuildDisplayListForChild(aBuilder, kid, lists);
+  }
+
+  tableBGs.MoveTo(aLists);
+  lists.MoveTo(aLists);
+
+  if (IsVisibleForPainting()) {
+    // In the collapsed border model, overlay all collapsed borders.
+    if (IsBorderCollapse()) {
+      if (HasBCBorders()) {
+        aLists.BorderBackground()->AppendNewToTop<nsDisplayTableBorderCollapse>(
+            aBuilder, this);
+      }
+    } else {
+      const nsStyleBorder* borderStyle = StyleBorder();
+      if (borderStyle->HasBorder()) {
+        aLists.BorderBackground()->AppendNewToTop<nsDisplayBorder>(aBuilder,
+                                                                   this);
+      }
+    }
+  }
+}
+
+LogicalSides nsTableFrame::GetLogicalSkipSides() const {
+  LogicalSides skip(mWritingMode);
+  if (MOZ_UNLIKELY(StyleBorder()->mBoxDecorationBreak ==
+                   StyleBoxDecorationBreak::Clone)) {
+    return skip;
+  }
+
+  // frame attribute was accounted for in nsHTMLTableElement::MapTableBorderInto
+  // account for pagination
+  if (GetPrevInFlow()) {
+    skip |= eLogicalSideBitsBStart;
+  }
+  if (GetNextInFlow()) {
+    skip |= eLogicalSideBitsBEnd;
+  }
+  return skip;
+}
+
+void nsTableFrame::SetColumnDimensions(nscoord aBSize, WritingMode aWM,
+                                       const LogicalMargin& aBorderPadding,
+                                       const nsSize& aContainerSize) {
+  const nscoord colBSize =
+      aBSize - (aBorderPadding.BStartEnd(aWM) + GetRowSpacing(-1) +
+                GetRowSpacing(GetRowCount()));
+  int32_t colIdx = 0;
+  LogicalPoint colGroupOrigin(aWM,
+                              aBorderPadding.IStart(aWM) + GetColSpacing(-1),
+                              aBorderPadding.BStart(aWM) + GetRowSpacing(-1));
+  nsTableFrame* fif = static_cast<nsTableFrame*>(FirstInFlow());
+  for (nsIFrame* colGroupFrame : mColGroups) {
+    MOZ_ASSERT(colGroupFrame->IsTableColGroupFrame());
+    // first we need to figure out the size of the colgroup
+    int32_t groupFirstCol = colIdx;
+    nscoord colGroupISize = 0;
+    nscoord colSpacing = 0;
+    const nsFrameList& columnList = colGroupFrame->PrincipalChildList();
+    for (nsIFrame* colFrame : columnList) {
+      if (mozilla::StyleDisplay::TableColumn ==
+          colFrame->StyleDisplay()->mDisplay) {
+        NS_ASSERTION(colIdx < GetColCount(), "invalid number of columns");
+        colSpacing = GetColSpacing(colIdx);
+        colGroupISize +=
+            fif->GetColumnISizeFromFirstInFlow(colIdx) + colSpacing;
+        ++colIdx;
+      }
+    }
+    if (colGroupISize) {
+      colGroupISize -= colSpacing;
+    }
+
+    LogicalRect colGroupRect(aWM, colGroupOrigin.I(aWM), colGroupOrigin.B(aWM),
+                             colGroupISize, colBSize);
+    colGroupFrame->SetRect(aWM, colGroupRect, aContainerSize);
+    nsSize colGroupSize = colGroupFrame->GetSize();
+
+    // then we can place the columns correctly within the group
+    colIdx = groupFirstCol;
+    LogicalPoint colOrigin(aWM);
+    for (nsIFrame* colFrame : columnList) {
+      if (mozilla::StyleDisplay::TableColumn ==
+          colFrame->StyleDisplay()->mDisplay) {
+        nscoord colISize = fif->GetColumnISizeFromFirstInFlow(colIdx);
+        LogicalRect colRect(aWM, colOrigin.I(aWM), colOrigin.B(aWM), colISize,
+                            colBSize);
+        colFrame->SetRect(aWM, colRect, colGroupSize);
+        colSpacing = GetColSpacing(colIdx);
+        colOrigin.I(aWM) += colISize + colSpacing;
+        ++colIdx;
+      }
+    }
+
+    colGroupOrigin.I(aWM) += colGroupISize + colSpacing;
+  }
+}
+
+// SEC: TODO need to worry about continuing frames prev/next in flow for
+// splitting across pages.
+
+// XXX this could be made more general to handle row modifications that change
+// the table bsize, but first we need to scrutinize every Invalidate
+void nsTableFrame::ProcessRowInserted(nscoord aNewBSize) {
+  SetRowInserted(false);  // reset the bit that got us here
+  RowGroupArray rowGroups = OrderedRowGroups();
+  // find the row group containing the inserted row
+  for (uint32_t rgIdx = 0; rgIdx < rowGroups.Length(); rgIdx++) {
+    nsTableRowGroupFrame* rgFrame = rowGroups[rgIdx];
+    NS_ASSERTION(rgFrame, "Must have rgFrame here");
+    // find the row that was inserted first
+    for (nsIFrame* childFrame : rgFrame->PrincipalChildList()) {
+      nsTableRowFrame* rowFrame = do_QueryFrame(childFrame);
+      if (rowFrame) {
+        if (rowFrame->IsFirstInserted()) {
+          rowFrame->SetFirstInserted(false);
+          // damage the table from the 1st row inserted to the end of the table
+          nsIFrame::InvalidateFrame();
+          // XXXbz didn't we do this up front?  Why do we need to do it again?
+          SetRowInserted(false);
+          return;  // found it, so leave
+        }
+      }
+    }
+  }
+}
+
+/* virtual */
+void nsTableFrame::MarkIntrinsicISizesDirty() {
+  nsITableLayoutStrategy* tls = LayoutStrategy();
+  if (MOZ_UNLIKELY(!tls)) {
+    // This is a FrameNeedsReflow() from nsBlockFrame::RemoveFrame()
+    // walking up the ancestor chain in a table next-in-flow.  In this case
+    // our original first-in-flow (which owns the TableLayoutStrategy) has
+    // already been destroyed and unhooked from the flow chain and thusly
+    // LayoutStrategy() returns null.  All the frames in the flow will be
+    // destroyed so no need to mark anything dirty here.  See bug 595758.
+    return;
+  }
+  tls->MarkIntrinsicISizesDirty();
+
+  // XXXldb Call SetBCDamageArea?
+
+  nsContainerFrame::MarkIntrinsicISizesDirty();
+}
+
+/* virtual */
+nscoord nsTableFrame::GetMinISize(gfxContext* aRenderingContext) {
+  if (NeedToCalcBCBorders()) CalcBCBorders();
+
+  ReflowColGroups(aRenderingContext);
+
+  return LayoutStrategy()->GetMinISize(aRenderingContext);
+}
+
+/* virtual */
+nscoord nsTableFrame::GetPrefISize(gfxContext* aRenderingContext) {
+  if (NeedToCalcBCBorders()) CalcBCBorders();
+
+  ReflowColGroups(aRenderingContext);
+
+  return LayoutStrategy()->GetPrefISize(aRenderingContext, false);
+}
+
+/* virtual */ nsIFrame::IntrinsicSizeOffsetData
+nsTableFrame::IntrinsicISizeOffsets(nscoord aPercentageBasis) {
+  IntrinsicSizeOffsetData result =
+      nsContainerFrame::IntrinsicISizeOffsets(aPercentageBasis);
+
+  result.margin = 0;
+
+  if (IsBorderCollapse()) {
+    result.padding = 0;
+
+    WritingMode wm = GetWritingMode();
+    LogicalMargin outerBC = GetIncludedOuterBCBorder(wm);
+    result.border = outerBC.IStartEnd(wm);
+  }
+
+  return result;
+}
+
+/* virtual */
+nsIFrame::SizeComputationResult nsTableFrame::ComputeSize(
+    gfxContext* aRenderingContext, WritingMode aWM, const LogicalSize& aCBSize,
+    nscoord aAvailableISize, const LogicalSize& aMargin,
+    const LogicalSize& aBorderPadding, const StyleSizeOverrides& aSizeOverrides,
+    ComputeSizeFlags aFlags) {
+  // Only table wrapper calls this method, and it should use our writing mode.
+  MOZ_ASSERT(aWM == GetWritingMode(),
+             "aWM should be the same as our writing mode!");
+
+  auto result = nsContainerFrame::ComputeSize(
+      aRenderingContext, aWM, aCBSize, aAvailableISize, aMargin, aBorderPadding,
+      aSizeOverrides, aFlags);
+
+  // If our containing block wants to override inner table frame's inline-size
+  // (e.g. when resolving flex base size), don't enforce the min inline-size
+  // later in this method.
+  if (aSizeOverrides.mApplyOverridesVerbatim && aSizeOverrides.mStyleISize &&
+      aSizeOverrides.mStyleISize->IsLengthPercentage()) {
+    return result;
+  }
+
+  // If we're a container for font size inflation, then shrink
+  // wrapping inside of us should not apply font size inflation.
+  AutoMaybeDisableFontInflation an(this);
+
+  // Tables never shrink below their min inline-size.
+  nscoord minISize = GetMinISize(aRenderingContext);
+  if (minISize > result.mLogicalSize.ISize(aWM)) {
+    result.mLogicalSize.ISize(aWM) = minISize;
+  }
+
+  return result;
+}
+
+nscoord nsTableFrame::TableShrinkISizeToFit(gfxContext* aRenderingContext,
+                                            nscoord aISizeInCB) {
+  // If we're a container for font size inflation, then shrink
+  // wrapping inside of us should not apply font size inflation.
+  AutoMaybeDisableFontInflation an(this);
+
+  nscoord result;
+  nscoord minISize = GetMinISize(aRenderingContext);
+  if (minISize > aISizeInCB) {
+    result = minISize;
+  } else {
+    // Tables shrink inline-size to fit with a slightly different algorithm
+    // from the one they use for their intrinsic isize (the difference
+    // relates to handling of percentage isizes on columns).  So this
+    // function differs from nsIFrame::ShrinkISizeToFit by only the
+    // following line.
+    // Since we've already called GetMinISize, we don't need to do any
+    // of the other stuff GetPrefISize does.
+    nscoord prefISize = LayoutStrategy()->GetPrefISize(aRenderingContext, true);
+    if (prefISize > aISizeInCB) {
+      result = aISizeInCB;
+    } else {
+      result = prefISize;
+    }
+  }
+  return result;
+}
+
+/* virtual */
+LogicalSize nsTableFrame::ComputeAutoSize(
+    gfxContext* aRenderingContext, WritingMode aWM, const LogicalSize& aCBSize,
+    nscoord aAvailableISize, const LogicalSize& aMargin,
+    const LogicalSize& aBorderPadding, const StyleSizeOverrides& aSizeOverrides,
+    ComputeSizeFlags aFlags) {
+  // Tables always shrink-wrap.
+  nscoord cbBased =
+      aAvailableISize - aMargin.ISize(aWM) - aBorderPadding.ISize(aWM);
+  return LogicalSize(aWM, TableShrinkISizeToFit(aRenderingContext, cbBased),
+                     NS_UNCONSTRAINEDSIZE);
+}
+
+// Return true if aParentReflowInput.frame or any of its ancestors within
+// the containing table have non-auto bsize. (e.g. pct or fixed bsize)
+bool nsTableFrame::AncestorsHaveStyleBSize(
+    const ReflowInput& aParentReflowInput) {
+  WritingMode wm = aParentReflowInput.GetWritingMode();
+  for (const ReflowInput* rs = &aParentReflowInput; rs && rs->mFrame;
+       rs = rs->mParentReflowInput) {
+    LayoutFrameType frameType = rs->mFrame->Type();
+    if (LayoutFrameType::TableCell == frameType ||
+        LayoutFrameType::TableRow == frameType ||
+        LayoutFrameType::TableRowGroup == frameType) {
+      const auto& bsize = rs->mStylePosition->BSize(wm);
+      // calc() with both lengths and percentages treated like 'auto' on
+      // internal table elements
+      if (!bsize.IsAuto() && !bsize.HasLengthAndPercentage()) {
+        return true;
+      }
+    } else if (LayoutFrameType::Table == frameType) {
+      // we reached the containing table, so always return
+      return !rs->mStylePosition->BSize(wm).IsAuto();
+    }
+  }
+  return false;
+}
+
+// See if a special block-size reflow needs to occur and if so,
+// call RequestSpecialBSizeReflow
+void nsTableFrame::CheckRequestSpecialBSizeReflow(
+    const ReflowInput& aReflowInput) {
+  NS_ASSERTION(aReflowInput.mFrame->IsTableCellFrame() ||
+                   aReflowInput.mFrame->IsTableRowFrame() ||
+                   aReflowInput.mFrame->IsTableRowGroupFrame() ||
+                   aReflowInput.mFrame->IsTableFrame(),
+               "unexpected frame type");
+  WritingMode wm = aReflowInput.GetWritingMode();
+  if (!aReflowInput.mFrame->GetPrevInFlow() &&  // 1st in flow
+      (NS_UNCONSTRAINEDSIZE ==
+           aReflowInput.ComputedBSize() ||  // no computed bsize
+       0 == aReflowInput.ComputedBSize()) &&
+      aReflowInput.mStylePosition->BSize(wm)
+          .ConvertsToPercentage() &&  // pct bsize
+      nsTableFrame::AncestorsHaveStyleBSize(*aReflowInput.mParentReflowInput)) {
+    nsTableFrame::RequestSpecialBSizeReflow(aReflowInput);
+  }
+}
+
+// Notify the frame and its ancestors (up to the containing table) that a
+// special bsize reflow will occur. During a special bsize reflow, a table, row
+// group, row, or cell returns the last size it was reflowed at. However, the
+// table may change the bsize of row groups, rows, cells in
+// DistributeBSizeToRows after. And the row group can change the bsize of rows,
+// cells in CalculateRowBSizes.
+void nsTableFrame::RequestSpecialBSizeReflow(const ReflowInput& aReflowInput) {
+  // notify the frame and its ancestors of the special reflow, stopping at the
+  // containing table
+  for (const ReflowInput* rs = &aReflowInput; rs && rs->mFrame;
+       rs = rs->mParentReflowInput) {
+    LayoutFrameType frameType = rs->mFrame->Type();
+    NS_ASSERTION(LayoutFrameType::TableCell == frameType ||
+                     LayoutFrameType::TableRow == frameType ||
+                     LayoutFrameType::TableRowGroup == frameType ||
+                     LayoutFrameType::Table == frameType,
+                 "unexpected frame type");
+
+    rs->mFrame->AddStateBits(NS_FRAME_CONTAINS_RELATIVE_BSIZE);
+    if (LayoutFrameType::Table == frameType) {
+      NS_ASSERTION(rs != &aReflowInput,
+                   "should not request special bsize reflow for table");
+      // always stop when we reach a table
+      break;
+    }
+  }
+}
+
+/******************************************************************************************
+ * Before reflow, intrinsic inline-size calculation is done using GetMinISize
+ * and GetPrefISize.  This used to be known as pass 1 reflow.
+ *
+ * After the intrinsic isize calculation, the table determines the
+ * column widths using BalanceColumnISizes() and
+ * then reflows each child again with a constrained avail isize. This reflow is
+ * referred to as the pass 2 reflow.
+ *
+ * A special bsize reflow (pass 3 reflow) can occur during an initial or resize
+ * reflow if (a) a row group, row, cell, or a frame inside a cell has a percent
+ * bsize but no computed bsize or (b) in paginated mode, a table has a bsize.
+ * (a) supports percent nested tables contained inside cells whose bsizes aren't
+ * known until after the pass 2 reflow. (b) is necessary because the table
+ * cannot split until after the pass 2 reflow. The mechanics of the special
+ * bsize reflow (variety a) are as follows:
+ *
+ * 1) Each table related frame (table, row group, row, cell) implements
+ *    NeedsSpecialReflow() to indicate that it should get the reflow. It does
+ *    this when it has a percent bsize but no computed bsize by calling
+ *    CheckRequestSpecialBSizeReflow(). This method calls
+ *    RequestSpecialBSizeReflow() which calls SetNeedSpecialReflow() on its
+ *    ancestors until it reaches the containing table and calls
+ *    SetNeedToInitiateSpecialReflow() on it. For percent bsize frames inside
+ *    cells, during DidReflow(), the cell's NotifyPercentBSize() is called
+ *    (the cell is the reflow input's mPercentBSizeObserver in this case).
+ *    NotifyPercentBSize() calls RequestSpecialBSizeReflow().
+ *
+ * XXX (jfkthame) This comment appears to be out of date; it refers to
+ * methods/flags that are no longer present in the code.
+ *
+ * 2) After the pass 2 reflow, if the table's NeedToInitiateSpecialReflow(true)
+ *    was called, it will do the special bsize reflow, setting the reflow
+ *    input's mFlags.mSpecialBSizeReflow to true and mSpecialHeightInitiator to
+ *    itself. It won't do this if IsPrematureSpecialHeightReflow() returns true
+ *    because in that case another special bsize reflow will be coming along
+ *    with the containing table as the mSpecialHeightInitiator. It is only
+ *    relevant to do the reflow when the mSpecialHeightInitiator is the
+ *    containing table, because if it is a remote ancestor, then appropriate
+ *    bsizes will not be known.
+ *
+ * 3) Since the bsizes of the table, row groups, rows, and cells was determined
+ *    during the pass 2 reflow, they return their last desired sizes during the
+ *    special bsize reflow. The reflow only permits percent bsize frames inside
+ *    the cells to resize based on the cells bsize and that bsize was
+ *    determined during the pass 2 reflow.
+ *
+ * So, in the case of deeply nested tables, all of the tables that were told to
+ * initiate a special reflow will do so, but if a table is already in a special
+ * reflow, it won't inititate the reflow until the current initiator is its
+ * containing table. Since these reflows are only received by frames that need
+ * them and they don't cause any rebalancing of tables, the extra overhead is
+ * minimal.
+ *
+ * The type of special reflow that occurs during printing (variety b) follows
+ * the same mechanism except that all frames will receive the reflow even if
+ * they don't really need them.
+ *
+ * Open issues with the special bsize reflow:
+ *
+ * 1) At some point there should be 2 kinds of special bsize reflows because (a)
+ *    and (b) above are really quite different. This would avoid unnecessary
+ *    reflows during printing.
+ *
+ * 2) When a cell contains frames whose percent bsizes > 100%, there is data
+ *    loss (see bug 115245). However, this can also occur if a cell has a fixed
+ *    bsize and there is no special bsize reflow.
+ *
+ * XXXldb Special bsize reflow should really be its own method, not
+ * part of nsIFrame::Reflow.  It should then call nsIFrame::Reflow on
+ * the contents of the cells to do the necessary block-axis resizing.
+ *
+ ******************************************************************************************/
+
+/* Layout the entire inner table. */
+void nsTableFrame::Reflow(nsPresContext* aPresContext,
+                          ReflowOutput& aDesiredSize,
+                          const ReflowInput& aReflowInput,
+                          nsReflowStatus& aStatus) {
+  MarkInReflow();
+  DO_GLOBAL_REFLOW_COUNT("nsTableFrame");
+  DISPLAY_REFLOW(aPresContext, this, aReflowInput, aDesiredSize, aStatus);
+  MOZ_ASSERT(aStatus.IsEmpty(), "Caller should pass a fresh reflow status!");
+  MOZ_ASSERT(!HasAnyStateBits(NS_FRAME_OUT_OF_FLOW),
+             "The nsTableWrapperFrame should be the out-of-flow if needed");
+
+  const WritingMode wm = aReflowInput.GetWritingMode();
+  MOZ_ASSERT(aReflowInput.ComputedLogicalMargin(wm).IsAllZero(),
+             "Only nsTableWrapperFrame can have margins!");
+
+  bool isPaginated = aPresContext->IsPaginated();
+
+  if (!GetPrevInFlow() && !mTableLayoutStrategy) {
+    NS_ERROR("strategy should have been created in Init");
+    return;
+  }
+
+  // see if collapsing borders need to be calculated
+  if (!GetPrevInFlow() && IsBorderCollapse() && NeedToCalcBCBorders()) {
+    CalcBCBorders();
+  }
+
+  // Check for an overflow list, and append any row group frames being pushed
+  MoveOverflowToChildList();
+
+  bool haveDesiredBSize = false;
+  SetHaveReflowedColGroups(false);
+
+  // Bug 1863421: We need to call ApplySkipSides() for borderPadding so that it
+  // is correct in a table continuation.
+  LogicalMargin borderPadding = aReflowInput.ComputedLogicalBorderPadding(wm);
+
+  // The tentative width is the width we assumed for the table when the child
+  // frames were positioned (which only matters in vertical-rl mode, because
+  // they're positioned relative to the right-hand edge). Then, after reflowing
+  // the kids, we can check whether the table ends up with a different width
+  // than this tentative value (either because it was unconstrained, so we used
+  // zero, or because it was enlarged by the child frames), we make the
+  // necessary positioning adjustments along the x-axis.
+  nscoord tentativeContainerWidth = 0;
+  bool mayAdjustXForAllChildren = false;
+
+  // Reflow the entire table (pass 2 and possibly pass 3). This phase is
+  // necessary during a constrained initial reflow and other reflows which
+  // require either a strategy init or balance. This isn't done during an
+  // unconstrained reflow, because it will occur later when the parent reflows
+  // with a constrained isize.
+  if (IsSubtreeDirty() || aReflowInput.ShouldReflowAllKids() ||
+      IsGeometryDirty() || isPaginated || aReflowInput.IsBResize() ||
+      NeedToCollapse()) {
+    if (aReflowInput.ComputedBSize() != NS_UNCONSTRAINEDSIZE ||
+        // Also check IsBResize(), to handle the first Reflow preceding a
+        // special bsize Reflow, when we've already had a special bsize
+        // Reflow (where ComputedBSize() would not be
+        // NS_UNCONSTRAINEDSIZE, but without a style change in between).
+        aReflowInput.IsBResize()) {
+      // XXX Eventually, we should modify DistributeBSizeToRows to use
+      // nsTableRowFrame::GetInitialBSize instead of nsIFrame::BSize().
+      // That way, it will make its calculations based on internal table
+      // frame bsizes as they are before they ever had any extra bsize
+      // distributed to them.  In the meantime, this reflows all the
+      // internal table frames, which restores them to their state before
+      // DistributeBSizeToRows was called.
+      SetGeometryDirty();
+    }
+
+    bool needToInitiateSpecialReflow = false;
+    if (isPaginated) {
+      // see if an extra reflow will be necessary in pagination mode
+      // when there is a specified table bsize
+      if (!GetPrevInFlow() &&
+          NS_UNCONSTRAINEDSIZE != aReflowInput.AvailableBSize()) {
+        nscoord tableSpecifiedBSize = CalcBorderBoxBSize(
+            aReflowInput, borderPadding, NS_UNCONSTRAINEDSIZE);
+        if (tableSpecifiedBSize != NS_UNCONSTRAINEDSIZE &&
+            tableSpecifiedBSize > 0) {
+          needToInitiateSpecialReflow = true;
+        }
+      }
+    } else {
+      needToInitiateSpecialReflow =
+          HasAnyStateBits(NS_FRAME_CONTAINS_RELATIVE_BSIZE);
+    }
+    nsIFrame* lastChildReflowed = nullptr;
+
+    NS_ASSERTION(!aReflowInput.mFlags.mSpecialBSizeReflow,
+                 "Shouldn't be in special bsize reflow here!");
+
+    const TableReflowMode firstReflowMode = needToInitiateSpecialReflow
+                                                ? TableReflowMode::Measuring
+                                                : TableReflowMode::Final;
+    ReflowTable(aDesiredSize, aReflowInput, borderPadding, firstReflowMode,
+                lastChildReflowed, aStatus);
+
+    // When in vertical-rl mode, there may be two kinds of scenarios in which
+    // the positioning of all the children need to be adjusted along the x-axis
+    // because the width we assumed for the table when the child frames were
+    // being positioned(i.e. tentative width) may be different from the final
+    // width for the table:
+    // 1. If the computed width for the table is unconstrained, a dummy zero
+    //    width was assumed as the tentative width to begin with.
+    // 2. If the child frames enlarge the width for the table, the final width
+    //    becomes larger than the tentative one.
+    // Let's record the tentative width here, if later the final width turns out
+    // to be different from this tentative one, it means one of the above
+    // scenarios happens, then we adjust positioning of all the children.
+    // Note that vertical-lr, unlike vertical-rl, doesn't need to take special
+    // care of this situation, because they're positioned relative to the
+    // left-hand edge.
+    const nsSize containerSize =
+        aReflowInput.ComputedSizeAsContainerIfConstrained();
+    if (wm.IsVerticalRL()) {
+      tentativeContainerWidth = containerSize.width;
+      mayAdjustXForAllChildren = true;
+    }
+
+    // reevaluate special bsize reflow conditions
+    if (HasAnyStateBits(NS_FRAME_CONTAINS_RELATIVE_BSIZE)) {
+      needToInitiateSpecialReflow = true;
+    }
+
+    // XXXldb Are all these conditions correct?
+    if (needToInitiateSpecialReflow && aStatus.IsComplete()) {
+      // XXXldb Do we need to set the IsBResize flag on any reflow inputs?
+
+      ReflowInput& mutable_rs = const_cast<ReflowInput&>(aReflowInput);
+
+      // distribute extra block-direction space to rows
+      aDesiredSize.BSize(wm) = CalcDesiredBSize(aReflowInput, borderPadding);
+      mutable_rs.mFlags.mSpecialBSizeReflow = true;
+
+      ReflowTable(aDesiredSize, aReflowInput, borderPadding,
+                  TableReflowMode::Final, lastChildReflowed, aStatus);
+
+      if (lastChildReflowed && aStatus.IsIncomplete()) {
+        // if there is an incomplete child, then set the desired bsize
+        // to include it but not the next one
+        aDesiredSize.BSize(wm) =
+            borderPadding.BEnd(wm) + GetRowSpacing(GetRowCount()) +
+            lastChildReflowed->GetLogicalNormalRect(wm, containerSize).BEnd(wm);
+      }
+      haveDesiredBSize = true;
+
+      mutable_rs.mFlags.mSpecialBSizeReflow = false;
+    }
+  }
+
+  aDesiredSize.ISize(wm) =
+      aReflowInput.ComputedISize() + borderPadding.IStartEnd(wm);
+  if (!haveDesiredBSize) {
+    aDesiredSize.BSize(wm) = CalcDesiredBSize(aReflowInput, borderPadding);
+  }
+  if (IsRowInserted()) {
+    ProcessRowInserted(aDesiredSize.BSize(wm));
+  }
+
+  // For more information on the reason for what we should do this, refer to the
+  // code which defines and evaluates the variables xAdjustmentForAllKids and
+  // tentativeContainerWidth in the previous part in this function.
+  if (mayAdjustXForAllChildren) {
+    nscoord xAdjustmentForAllKids =
+        aDesiredSize.Width() - tentativeContainerWidth;
+    if (0 != xAdjustmentForAllKids) {
+      for (nsIFrame* kid : mFrames) {
+        kid->MovePositionBy(nsPoint(xAdjustmentForAllKids, 0));
+        RePositionViews(kid);
+      }
+    }
+  }
+
+  // Calculate the overflow area contribution from our children. We couldn't
+  // do this on the fly during ReflowChildren(), because in vertical-rl mode
+  // with unconstrained width, we weren't placing them in their final positions
+  // until the fixupKidPositions loop just above.
+  for (nsIFrame* kid : mFrames) {
+    ConsiderChildOverflow(aDesiredSize.mOverflowAreas, kid);
+  }
+
+  SetColumnDimensions(aDesiredSize.BSize(wm), wm, borderPadding,
+                      aDesiredSize.PhysicalSize());
+  NS_WARNING_ASSERTION(NS_UNCONSTRAINEDSIZE != aReflowInput.AvailableISize(),
+                       "reflow branch removed unconstrained available isizes");
+  if (NeedToCollapse()) {
+    // This code and the code it depends on assumes that all row groups
+    // and rows have just been reflowed (i.e., it makes adjustments to
+    // their rects that are not idempotent).  Thus the reflow code
+    // checks NeedToCollapse() to ensure this is true.
+    AdjustForCollapsingRowsCols(aDesiredSize, wm, borderPadding);
+  }
+
+  // If there are any relatively-positioned table parts, we need to reflow their
+  // absolutely-positioned descendants now that their dimensions are final.
+  FixupPositionedTableParts(aPresContext, aDesiredSize, aReflowInput);
+
+  // make sure the table overflow area does include the table rect.
+  nsRect tableRect(0, 0, aDesiredSize.Width(), aDesiredSize.Height());
+
+  if (ShouldApplyOverflowClipping(aReflowInput.mStyleDisplay) !=
+      PhysicalAxes::Both) {
+    // collapsed border may leak out
+    LogicalMargin bcMargin = GetExcludedOuterBCBorder(wm);
+    tableRect.Inflate(bcMargin.GetPhysicalMargin(wm));
+  }
+  aDesiredSize.mOverflowAreas.UnionAllWith(tableRect);
+
+  FinishAndStoreOverflow(&aDesiredSize);
+}
+
+void nsTableFrame::FixupPositionedTableParts(nsPresContext* aPresContext,
+                                             ReflowOutput& aDesiredSize,
+                                             const ReflowInput& aReflowInput) {
+  FrameTArray* positionedParts = GetProperty(PositionedTablePartArray());
+  if (!positionedParts) {
+    return;
+  }
+
+  OverflowChangedTracker overflowTracker;
+  overflowTracker.SetSubtreeRoot(this);
+
+  for (size_t i = 0; i < positionedParts->Length(); ++i) {
+    nsIFrame* positionedPart = positionedParts->ElementAt(i);
+
+    // As we've already finished reflow, positionedParts's size and overflow
+    // areas have already been assigned, so we just pull them back out.
+    const WritingMode wm = positionedPart->GetWritingMode();
+    const LogicalSize size = positionedPart->GetLogicalSize(wm);
+    ReflowOutput desiredSize(aReflowInput.GetWritingMode());
+    desiredSize.SetSize(wm, size);
+    desiredSize.mOverflowAreas =
+        positionedPart->GetOverflowAreasRelativeToSelf();
+
+    // Construct a dummy reflow input and reflow status.
+    // XXX(seth): Note that the dummy reflow input doesn't have a correct
+    // chain of parent reflow inputs. It also doesn't necessarily have a
+    // correct containing block.
+    LogicalSize availSize = size;
+    availSize.BSize(wm) = NS_UNCONSTRAINEDSIZE;
+    ReflowInput reflowInput(aPresContext, positionedPart,
+                            aReflowInput.mRenderingContext, availSize,
+                            ReflowInput::InitFlag::DummyParentReflowInput);
+    nsReflowStatus reflowStatus;
+
+    // Reflow absolutely-positioned descendants of the positioned part.
+    // FIXME: Unconditionally using NS_UNCONSTRAINEDSIZE for the bsize and
+    // ignoring any change to the reflow status aren't correct. We'll never
+    // paginate absolutely positioned frames.
+    positionedPart->FinishReflowWithAbsoluteFrames(
+        PresContext(), desiredSize, reflowInput, reflowStatus, true);
+
+    // FinishReflowWithAbsoluteFrames has updated overflow on
+    // |positionedPart|.  We need to make sure that update propagates
+    // through the intermediate frames between it and this frame.
+    nsIFrame* positionedFrameParent = positionedPart->GetParent();
+    if (positionedFrameParent != this) {
+      overflowTracker.AddFrame(positionedFrameParent,
+                               OverflowChangedTracker::CHILDREN_CHANGED);
+    }
+  }
+
+  // Propagate updated overflow areas up the tree.
+  overflowTracker.Flush();
+
+  // Update our own overflow areas. (OverflowChangedTracker doesn't update the
+  // subtree root itself.)
+  aDesiredSize.SetOverflowAreasToDesiredBounds();
+  nsLayoutUtils::UnionChildOverflow(this, aDesiredSize.mOverflowAreas);
+}
+
+bool nsTableFrame::ComputeCustomOverflow(OverflowAreas& aOverflowAreas) {
+  // As above in Reflow, make sure the table overflow area includes the table
+  // rect, and check for collapsed borders leaking out.
+  if (ShouldApplyOverflowClipping(StyleDisplay()) != PhysicalAxes::Both) {
+    nsRect bounds(nsPoint(0, 0), GetSize());
+    WritingMode wm = GetWritingMode();
+    LogicalMargin bcMargin = GetExcludedOuterBCBorder(wm);
+    bounds.Inflate(bcMargin.GetPhysicalMargin(wm));
+
+    aOverflowAreas.UnionAllWith(bounds);
+  }
+  return nsContainerFrame::ComputeCustomOverflow(aOverflowAreas);
+}
+
+void nsTableFrame::ReflowTable(ReflowOutput& aDesiredSize,
+                               const ReflowInput& aReflowInput,
+                               const LogicalMargin& aBorderPadding,
+                               TableReflowMode aReflowMode,
+                               nsIFrame*& aLastChildReflowed,
+                               nsReflowStatus& aStatus) {
+  aLastChildReflowed = nullptr;
+
+  if (!GetPrevInFlow()) {
+    mTableLayoutStrategy->ComputeColumnISizes(aReflowInput);
+  }
+
+  TableReflowInput reflowInput(aReflowInput, aBorderPadding, aReflowMode);
+  ReflowChildren(reflowInput, aStatus, aLastChildReflowed,
+                 aDesiredSize.mOverflowAreas);
+
+  ReflowColGroups(aReflowInput.mRenderingContext);
+}
+
+void nsTableFrame::PushChildrenToOverflow(const RowGroupArray& aRowGroups,
+                                          size_t aPushFrom) {
+  MOZ_ASSERT(aPushFrom > 0, "pushing first child");
+
+  // Extract the frames from the array into a frame list.
+  nsFrameList frames;
+  for (size_t childX = aPushFrom; childX < aRowGroups.Length(); ++childX) {
+    nsTableRowGroupFrame* rgFrame = aRowGroups[childX];
+    if (!rgFrame->IsRepeatable()) {
+      mFrames.RemoveFrame(rgFrame);
+      frames.AppendFrame(nullptr, rgFrame);
+    }
+  }
+
+  if (frames.IsEmpty()) {
+    return;
+  }
+
+  // Add the frames to our overflow list.
+  SetOverflowFrames(std::move(frames));
+}
+
+// collapsing row groups, rows, col groups and cols are accounted for after both
+// passes of reflow so that it has no effect on the calculations of reflow.
+void nsTableFrame::AdjustForCollapsingRowsCols(
+    ReflowOutput& aDesiredSize, const WritingMode aWM,
+    const LogicalMargin& aBorderPadding) {
+  nscoord bTotalOffset = 0;  // total offset among all rows in all row groups
+
+  // reset the bit, it will be set again if row/rowgroup or col/colgroup are
+  // collapsed
+  SetNeedToCollapse(false);
+
+  // collapse the rows and/or row groups as necessary
+  // Get the ordered children
+  RowGroupArray rowGroups = OrderedRowGroups();
+
+  nsTableFrame* firstInFlow = static_cast<nsTableFrame*>(FirstInFlow());
+  nscoord iSize = firstInFlow->GetCollapsedISize(aWM, aBorderPadding);
+  nscoord rgISize = iSize - GetColSpacing(-1) - GetColSpacing(GetColCount());
+  OverflowAreas overflow;
+  // Walk the list of children
+  for (uint32_t childX = 0; childX < rowGroups.Length(); childX++) {
+    nsTableRowGroupFrame* rgFrame = rowGroups[childX];
+    NS_ASSERTION(rgFrame, "Must have row group frame here");
+    bTotalOffset +=
+        rgFrame->CollapseRowGroupIfNecessary(bTotalOffset, rgISize, aWM);
+    ConsiderChildOverflow(overflow, rgFrame);
+  }
+
+  aDesiredSize.BSize(aWM) -= bTotalOffset;
+  aDesiredSize.ISize(aWM) = iSize;
+  overflow.UnionAllWith(
+      nsRect(0, 0, aDesiredSize.Width(), aDesiredSize.Height()));
+  FinishAndStoreOverflow(overflow,
+                         nsSize(aDesiredSize.Width(), aDesiredSize.Height()));
+}
+
+nscoord nsTableFrame::GetCollapsedISize(const WritingMode aWM,
+                                        const LogicalMargin& aBorderPadding) {
+  NS_ASSERTION(!GetPrevInFlow(), "GetCollapsedISize called on next in flow");
+  nscoord iSize = GetColSpacing(GetColCount());
+  iSize += aBorderPadding.IStartEnd(aWM);
+  nsTableFrame* fif = static_cast<nsTableFrame*>(FirstInFlow());
+  for (nsIFrame* groupFrame : mColGroups) {
+    const nsStyleVisibility* groupVis = groupFrame->StyleVisibility();
+    bool collapseGroup = StyleVisibility::Collapse == groupVis->mVisible;
+    nsTableColGroupFrame* cgFrame = (nsTableColGroupFrame*)groupFrame;
+    for (nsTableColFrame* colFrame = cgFrame->GetFirstColumn(); colFrame;
+         colFrame = colFrame->GetNextCol()) {
+      const nsStyleDisplay* colDisplay = colFrame->StyleDisplay();
+      nscoord colIdx = colFrame->GetColIndex();
+      if (mozilla::StyleDisplay::TableColumn == colDisplay->mDisplay) {
+        const nsStyleVisibility* colVis = colFrame->StyleVisibility();
+        bool collapseCol = StyleVisibility::Collapse == colVis->mVisible;
+        nscoord colISize = fif->GetColumnISizeFromFirstInFlow(colIdx);
+        if (!collapseGroup && !collapseCol) {
+          iSize += colISize;
+          if (ColumnHasCellSpacingBefore(colIdx)) {
+            iSize += GetColSpacing(colIdx - 1);
+          }
+        } else {
+          SetNeedToCollapse(true);
+        }
+      }
+    }
+  }
+  return iSize;
+}
+
+/* virtual */
+void nsTableFrame::DidSetComputedStyle(ComputedStyle* aOldComputedStyle) {
+  nsContainerFrame::DidSetComputedStyle(aOldComputedStyle);
+
+  if (!aOldComputedStyle)  // avoid this on init
+    return;
+
+  if (IsBorderCollapse() && BCRecalcNeeded(aOldComputedStyle, Style())) {
+    SetFullBCDamageArea();
+  }
+
+  // avoid this on init or nextinflow
+  if (!mTableLayoutStrategy || GetPrevInFlow()) return;
+
+  bool isAuto = IsAutoLayout();
+  if (isAuto != (LayoutStrategy()->GetType() == nsITableLayoutStrategy::Auto)) {
+    if (isAuto)
+      mTableLayoutStrategy = MakeUnique<BasicTableLayoutStrategy>(this);
+    else
+      mTableLayoutStrategy = MakeUnique<FixedTableLayoutStrategy>(this);
+  }
+}
+
+void nsTableFrame::AppendFrames(ChildListID aListID, nsFrameList&& aFrameList) {
+  NS_ASSERTION(aListID == FrameChildListID::Principal ||
+                   aListID == FrameChildListID::ColGroup,
+               "unexpected child list");
+
+  // Because we actually have two child lists, one for col group frames and one
+  // for everything else, we need to look at each frame individually
+  // XXX The frame construction code should be separating out child frames
+  // based on the type, bug 343048.
+  while (!aFrameList.IsEmpty()) {
+    nsIFrame* f = aFrameList.FirstChild();
+    aFrameList.RemoveFrame(f);
+
+    // See what kind of frame we have
+    const nsStyleDisplay* display = f->StyleDisplay();
+
+    if (mozilla::StyleDisplay::TableColumnGroup == display->mDisplay) {
+      if (MOZ_UNLIKELY(GetPrevInFlow())) {
+        nsFrameList colgroupFrame(f, f);
+        auto firstInFlow = static_cast<nsTableFrame*>(FirstInFlow());
+        firstInFlow->AppendFrames(aListID, std::move(colgroupFrame));
+        continue;
+      }
+      nsTableColGroupFrame* lastColGroup =
+          nsTableColGroupFrame::GetLastRealColGroup(this);
+      int32_t startColIndex = (lastColGroup)
+                                  ? lastColGroup->GetStartColumnIndex() +
+                                        lastColGroup->GetColCount()
+                                  : 0;
+      mColGroups.InsertFrame(this, lastColGroup, f);
+      // Insert the colgroup and its cols into the table
+      InsertColGroups(startColIndex,
+                      nsFrameList::Slice(f, f->GetNextSibling()));
+    } else if (IsRowGroup(display->mDisplay)) {
+      DrainSelfOverflowList();  // ensure the last frame is in mFrames
+      // Append the new row group frame to the sibling chain
+      mFrames.AppendFrame(nullptr, f);
+
+      // insert the row group and its rows into the table
+      InsertRowGroups(nsFrameList::Slice(f, nullptr));
+    } else {
+      // Nothing special to do, just add the frame to our child list
+      MOZ_ASSERT_UNREACHABLE(
+          "How did we get here? Frame construction screwed up");
+      mFrames.AppendFrame(nullptr, f);
+    }
+  }
+
+#ifdef DEBUG_TABLE_CELLMAP
+  printf("=== TableFrame::AppendFrames\n");
+  Dump(true, true, true);
+#endif
+  PresShell()->FrameNeedsReflow(this, IntrinsicDirty::FrameAndAncestors,
+                                NS_FRAME_HAS_DIRTY_CHILDREN);
+  SetGeometryDirty();
+}
+
+void nsTableFrame::InsertFrames(ChildListID aListID, nsIFrame* aPrevFrame,
+                                const nsLineList::iterator* aPrevFrameLine,
+                                nsFrameList&& aFrameList) {
+  // The frames in aFrameList can be a mix of row group frames and col group
+  // frames. The problem is that they should go in separate child lists so
+  // we need to deal with that here...
+  // XXX The frame construction code should be separating out child frames
+  // based on the type, bug 343048.
+
+  NS_ASSERTION(!aPrevFrame || aPrevFrame->GetParent() == this,
+               "inserting after sibling frame with different parent");
+
+  if ((aPrevFrame && !aPrevFrame->GetNextSibling()) ||
+      (!aPrevFrame && GetChildList(aListID).IsEmpty())) {
+    // Treat this like an append; still a workaround for bug 343048.
+    AppendFrames(aListID, std::move(aFrameList));
+    return;
+  }
+
+  // Collect ColGroupFrames into a separate list and insert those separately
+  // from the other frames (bug 759249).
+  nsFrameList colGroupList;
+  nsFrameList principalList;
+  do {
+    const auto display = aFrameList.FirstChild()->StyleDisplay()->mDisplay;
+    nsFrameList head = aFrameList.Split([display](nsIFrame* aFrame) {
+      return aFrame->StyleDisplay()->mDisplay != display;
+    });
+    if (display == mozilla::StyleDisplay::TableColumnGroup) {
+      colGroupList.AppendFrames(nullptr, std::move(head));
+    } else {
+      principalList.AppendFrames(nullptr, std::move(head));
+    }
+  } while (aFrameList.NotEmpty());
+
+  // We pass aPrevFrame for both ColGroup and other frames since
+  // HomogenousInsertFrames will only use it if it's a suitable
+  // prev-sibling for the frames in the frame list.
+  if (colGroupList.NotEmpty()) {
+    HomogenousInsertFrames(FrameChildListID::ColGroup, aPrevFrame,
+                           colGroupList);
+  }
+  if (principalList.NotEmpty()) {
+    HomogenousInsertFrames(FrameChildListID::Principal, aPrevFrame,
+                           principalList);
+  }
+}
+
+void nsTableFrame::HomogenousInsertFrames(ChildListID aListID,
+                                          nsIFrame* aPrevFrame,
+                                          nsFrameList& aFrameList) {
+  // See what kind of frame we have
+  const nsStyleDisplay* display = aFrameList.FirstChild()->StyleDisplay();
+  bool isColGroup =
+      mozilla::StyleDisplay::TableColumnGroup == display->mDisplay;
+#ifdef DEBUG
+  // Verify that either all siblings have display:table-column-group, or they
+  // all have display values different from table-column-group.
+  for (nsIFrame* frame : aFrameList) {
+    auto nextDisplay = frame->StyleDisplay()->mDisplay;
+    MOZ_ASSERT(
+        isColGroup == (nextDisplay == mozilla::StyleDisplay::TableColumnGroup),
+        "heterogenous childlist");
+  }
+#endif
+  if (MOZ_UNLIKELY(isColGroup && GetPrevInFlow())) {
+    auto firstInFlow = static_cast<nsTableFrame*>(FirstInFlow());
+    firstInFlow->AppendFrames(aListID, std::move(aFrameList));
+    return;
+  }
+  if (aPrevFrame) {
+    const nsStyleDisplay* prevDisplay = aPrevFrame->StyleDisplay();
+    // Make sure they belong on the same frame list
+    if ((display->mDisplay == mozilla::StyleDisplay::TableColumnGroup) !=
+        (prevDisplay->mDisplay == mozilla::StyleDisplay::TableColumnGroup)) {
+      // the previous frame is not valid, see comment at ::AppendFrames
+      // XXXbz Using content indices here means XBL will get screwed
+      // over...  Oh, well.
+      nsIFrame* pseudoFrame = aFrameList.FirstChild();
+      nsIContent* parentContent = GetContent();
+      nsIContent* content = nullptr;
+      aPrevFrame = nullptr;
+      while (pseudoFrame &&
+             (parentContent == (content = pseudoFrame->GetContent()))) {
+        pseudoFrame = pseudoFrame->PrincipalChildList().FirstChild();
+      }
+      nsCOMPtr<nsIContent> container = content->GetParent();
+      if (MOZ_LIKELY(container)) {  // XXX need this null-check, see bug 411823.
+        const Maybe<uint32_t> newIndex = container->ComputeIndexOf(content);
+        nsIFrame* kidFrame;
+        nsTableColGroupFrame* lastColGroup = nullptr;
+        if (isColGroup) {
+          kidFrame = mColGroups.FirstChild();
+          lastColGroup = nsTableColGroupFrame::GetLastRealColGroup(this);
+        } else {
+          kidFrame = mFrames.FirstChild();
+        }
+        // Important: need to start at a value smaller than all valid indices
+        Maybe<uint32_t> lastIndex;
+        while (kidFrame) {
+          if (isColGroup) {
+            if (kidFrame == lastColGroup) {
+              aPrevFrame =
+                  kidFrame;  // there is no real colgroup after this one
+              break;
+            }
+          }
+          pseudoFrame = kidFrame;
+          while (pseudoFrame &&
+                 (parentContent == (content = pseudoFrame->GetContent()))) {
+            pseudoFrame = pseudoFrame->PrincipalChildList().FirstChild();
+          }
+          const Maybe<uint32_t> index = container->ComputeIndexOf(content);
+          // XXX Keep the odd traditional behavior in some indices are nothing
+          //     cases for now.
+          if ((index.isSome() &&
+               (lastIndex.isNothing() || *index > *lastIndex)) &&
+              (newIndex.isSome() &&
+               (index.isNothing() || *index < *newIndex))) {
+            lastIndex = index;
+            aPrevFrame = kidFrame;
+          }
+          kidFrame = kidFrame->GetNextSibling();
+        }
+      }
+    }
+  }
+  if (mozilla::StyleDisplay::TableColumnGroup == display->mDisplay) {
+    NS_ASSERTION(aListID == FrameChildListID::ColGroup,
+                 "unexpected child list");
+    // Insert the column group frames
+    const nsFrameList::Slice& newColgroups =
+        mColGroups.InsertFrames(this, aPrevFrame, std::move(aFrameList));
+    // find the starting col index for the first new col group
+    int32_t startColIndex = 0;
+    if (aPrevFrame) {
+      nsTableColGroupFrame* prevColGroup =
+          (nsTableColGroupFrame*)GetFrameAtOrBefore(
+              this, aPrevFrame, LayoutFrameType::TableColGroup);
+      if (prevColGroup) {
+        startColIndex =
+            prevColGroup->GetStartColumnIndex() + prevColGroup->GetColCount();
+      }
+    }
+    InsertColGroups(startColIndex, newColgroups);
+  } else if (IsRowGroup(display->mDisplay)) {
+    NS_ASSERTION(aListID == FrameChildListID::Principal,
+                 "unexpected child list");
+    DrainSelfOverflowList();  // ensure aPrevFrame is in mFrames
+    // Insert the frames in the sibling chain
+    const nsFrameList::Slice& newRowGroups =
+        mFrames.InsertFrames(nullptr, aPrevFrame, std::move(aFrameList));
+
+    InsertRowGroups(newRowGroups);
+  } else {
+    NS_ASSERTION(aListID == FrameChildListID::Principal,
+                 "unexpected child list");
+    MOZ_ASSERT_UNREACHABLE("How did we even get here?");
+    // Just insert the frame and don't worry about reflowing it
+    mFrames.InsertFrames(nullptr, aPrevFrame, std::move(aFrameList));
+    return;
+  }
+
+  PresShell()->FrameNeedsReflow(this, IntrinsicDirty::FrameAndAncestors,
+                                NS_FRAME_HAS_DIRTY_CHILDREN);
+  SetGeometryDirty();
+#ifdef DEBUG_TABLE_CELLMAP
+  printf("=== TableFrame::InsertFrames\n");
+  Dump(true, true, true);
+#endif
+}
+
+void nsTableFrame::DoRemoveFrame(DestroyContext& aContext, ChildListID aListID,
+                                 nsIFrame* aOldFrame) {
+  if (aListID == FrameChildListID::ColGroup) {
+    nsIFrame* nextColGroupFrame = aOldFrame->GetNextSibling();
+    nsTableColGroupFrame* colGroup = (nsTableColGroupFrame*)aOldFrame;
+    int32_t firstColIndex = colGroup->GetStartColumnIndex();
+    int32_t lastColIndex = firstColIndex + colGroup->GetColCount() - 1;
+    mColGroups.DestroyFrame(aContext, aOldFrame);
+    nsTableColGroupFrame::ResetColIndices(nextColGroupFrame, firstColIndex);
+    // remove the cols from the table
+    int32_t colIdx;
+    for (colIdx = lastColIndex; colIdx >= firstColIndex; colIdx--) {
+      nsTableColFrame* colFrame = mColFrames.SafeElementAt(colIdx);
+      if (colFrame) {
+        RemoveCol(colGroup, colIdx, true, false);
+      }
+    }
+
+    // If we have some anonymous cols at the end already, we just
+    // add more of them.
+    if (!mColFrames.IsEmpty() &&
+        mColFrames.LastElement() &&  // XXXbz is this ever null?
+        mColFrames.LastElement()->GetColType() == eColAnonymousCell) {
+      int32_t numAnonymousColsToAdd = GetColCount() - mColFrames.Length();
+      if (numAnonymousColsToAdd > 0) {
+        // this sets the child list, updates the col cache and cell map
+        AppendAnonymousColFrames(numAnonymousColsToAdd);
+      }
+    } else {
+      // All of our colframes correspond to actual <col> tags.  It's possible
+      // that we still have at least as many <col> tags as we have logical
+      // columns from cells, but we might have one less.  Handle the latter case
+      // as follows: First ask the cellmap to drop its last col if it doesn't
+      // have any actual cells in it.  Then call MatchCellMapToColCache to
+      // append an anonymous column if it's needed; this needs to be after
+      // RemoveColsAtEnd, since it will determine the need for a new column
+      // frame based on the width of the cell map.
+      nsTableCellMap* cellMap = GetCellMap();
+      if (cellMap) {  // XXXbz is this ever null?
+        cellMap->RemoveColsAtEnd();
+        MatchCellMapToColCache(cellMap);
+      }
+    }
+
+  } else {
+    NS_ASSERTION(aListID == FrameChildListID::Principal,
+                 "unexpected child list");
+    nsTableRowGroupFrame* rgFrame =
+        static_cast<nsTableRowGroupFrame*>(aOldFrame);
+    // remove the row group from the cell map
+    nsTableCellMap* cellMap = GetCellMap();
+    if (cellMap) {
+      cellMap->RemoveGroupCellMap(rgFrame);
+    }
+
+    // remove the row group frame from the sibling chain
+    mFrames.DestroyFrame(aContext, aOldFrame);
+
+    // the removal of a row group changes the cellmap, the columns might change
+    if (cellMap) {
+      cellMap->Synchronize(this);
+      // Create an empty slice
+      ResetRowIndices(nsFrameList::Slice(nullptr, nullptr));
+      TableArea damageArea;
+      cellMap->RebuildConsideringCells(nullptr, nullptr, 0, 0, false,
+                                       damageArea);
+
+      static_cast<nsTableFrame*>(FirstInFlow())
+          ->MatchCellMapToColCache(cellMap);
+    }
+  }
+}
+
+void nsTableFrame::RemoveFrame(DestroyContext& aContext, ChildListID aListID,
+                               nsIFrame* aOldFrame) {
+  NS_ASSERTION(aListID == FrameChildListID::ColGroup ||
+                   mozilla::StyleDisplay::TableColumnGroup !=
+                       aOldFrame->StyleDisplay()->mDisplay,
+               "Wrong list name; use FrameChildListID::ColGroup iff colgroup");
+  mozilla::PresShell* presShell = PresShell();
+  nsTableFrame* lastParent = nullptr;
+  while (aOldFrame) {
+    nsIFrame* oldFrameNextContinuation = aOldFrame->GetNextContinuation();
+    nsTableFrame* parent = static_cast<nsTableFrame*>(aOldFrame->GetParent());
+    if (parent != lastParent) {
+      parent->DrainSelfOverflowList();
+    }
+    parent->DoRemoveFrame(aContext, aListID, aOldFrame);
+    aOldFrame = oldFrameNextContinuation;
+    if (parent != lastParent) {
+      // for now, just bail and recalc all of the collapsing borders
+      // as the cellmap changes we need to recalc
+      if (parent->IsBorderCollapse()) {
+        parent->SetFullBCDamageArea();
+      }
+      parent->SetGeometryDirty();
+      presShell->FrameNeedsReflow(parent, IntrinsicDirty::FrameAndAncestors,
+                                  NS_FRAME_HAS_DIRTY_CHILDREN);
+      lastParent = parent;
+    }
+  }
+#ifdef DEBUG_TABLE_CELLMAP
+  printf("=== TableFrame::RemoveFrame\n");
+  Dump(true, true, true);
+#endif
+}
+
+/* virtual */
+nsMargin nsTableFrame::GetUsedBorder() const {
+  if (!IsBorderCollapse()) return nsContainerFrame::GetUsedBorder();
+
+  WritingMode wm = GetWritingMode();
+  return GetIncludedOuterBCBorder(wm).GetPhysicalMargin(wm);
+}
+
+/* virtual */
+nsMargin nsTableFrame::GetUsedPadding() const {
+  if (!IsBorderCollapse()) return nsContainerFrame::GetUsedPadding();
+
+  return nsMargin(0, 0, 0, 0);
+}
+
+/* virtual */
+nsMargin nsTableFrame::GetUsedMargin() const {
+  // The margin is inherited to the table wrapper frame via
+  // the ::-moz-table-wrapper rule in ua.css.
+  return nsMargin(0, 0, 0, 0);
+}
+
+// This property is only set on the first-in-flow of nsTableFrame.
+NS_DECLARE_FRAME_PROPERTY_DELETABLE(TableBCDataProperty, TableBCData)
+
+TableBCData* nsTableFrame::GetTableBCData() const {
+  return FirstInFlow()->GetProperty(TableBCDataProperty());
+}
+
+TableBCData* nsTableFrame::GetOrCreateTableBCData() {
+  MOZ_ASSERT(!GetPrevInFlow(),
+             "TableBCProperty should only be set on the first-in-flow!");
+  TableBCData* value = GetProperty(TableBCDataProperty());
+  if (!value) {
+    value = new TableBCData();
+    SetProperty(TableBCDataProperty(), value);
+  }
+
+  MOZ_ASSERT(value, "TableBCData must exist!");
+  return value;
+}
+
+static void DivideBCBorderSize(BCPixelSize aPixelSize, BCPixelSize& aSmallHalf,
+                               BCPixelSize& aLargeHalf) {
+  aSmallHalf = aPixelSize / 2;
+  aLargeHalf = aPixelSize - aSmallHalf;
+}
+
+LogicalMargin nsTableFrame::GetOuterBCBorder(const WritingMode aWM) const {
+  if (NeedToCalcBCBorders()) {
+    const_cast<nsTableFrame*>(this)->CalcBCBorders();
+  }
+  int32_t d2a = PresContext()->AppUnitsPerDevPixel();
+  TableBCData* propData = GetTableBCData();
+  if (propData) {
+    return LogicalMargin(
+        aWM, BC_BORDER_START_HALF_COORD(d2a, propData->mBStartBorderWidth),
+        BC_BORDER_END_HALF_COORD(d2a, propData->mIEndBorderWidth),
+        BC_BORDER_END_HALF_COORD(d2a, propData->mBEndBorderWidth),
+        BC_BORDER_START_HALF_COORD(d2a, propData->mIStartBorderWidth));
+  }
+  return LogicalMargin(aWM);
+}
+
+LogicalMargin nsTableFrame::GetIncludedOuterBCBorder(
+    const WritingMode aWM) const {
+  if (NeedToCalcBCBorders()) {
+    const_cast<nsTableFrame*>(this)->CalcBCBorders();
+  }
+
+  int32_t d2a = PresContext()->AppUnitsPerDevPixel();
+  TableBCData* propData = GetTableBCData();
+  if (propData) {
+    return LogicalMargin(
+        aWM, BC_BORDER_START_HALF_COORD(d2a, propData->mBStartBorderWidth),
+        BC_BORDER_END_HALF_COORD(d2a, propData->mIEndCellBorderWidth),
+        BC_BORDER_END_HALF_COORD(d2a, propData->mBEndBorderWidth),
+        BC_BORDER_START_HALF_COORD(d2a, propData->mIStartCellBorderWidth));
+  }
+  return LogicalMargin(aWM);
+}
+
+LogicalMargin nsTableFrame::GetExcludedOuterBCBorder(
+    const WritingMode aWM) const {
+  return GetOuterBCBorder(aWM) - GetIncludedOuterBCBorder(aWM);
+}
+
+void nsTableFrame::GetCollapsedBorderPadding(
+    Maybe<LogicalMargin>& aBorder, Maybe<LogicalMargin>& aPadding) const {
+  if (IsBorderCollapse()) {
+    // Border-collapsed tables don't use any of their padding, and only part of
+    // their border.
+    const auto wm = GetWritingMode();
+    aBorder.emplace(GetIncludedOuterBCBorder(wm));
+    aPadding.emplace(wm);
+  }
+}
+
+void nsTableFrame::InitChildReflowInput(ReflowInput& aReflowInput) {
+  const auto childWM = aReflowInput.GetWritingMode();
+  LogicalMargin border(childWM);
+  if (IsBorderCollapse()) {
+    nsTableRowGroupFrame* rgFrame =
+        static_cast<nsTableRowGroupFrame*>(aReflowInput.mFrame);
+    border = rgFrame->GetBCBorderWidth(childWM);
+  }
+  const LogicalMargin zeroPadding(childWM);
+  aReflowInput.Init(PresContext(), Nothing(), Some(border), Some(zeroPadding));
+
+  NS_ASSERTION(!mBits.mResizedColumns ||
+                   !aReflowInput.mParentReflowInput->mFlags.mSpecialBSizeReflow,
+               "should not resize columns on special bsize reflow");
+  if (mBits.mResizedColumns) {
+    aReflowInput.SetIResize(true);
+  }
+}
+
+// Position and size aKidFrame and update our reflow input. The origin of
+// aKidRect is relative to the upper-left origin of our frame
+void nsTableFrame::PlaceChild(TableReflowInput& aReflowInput,
+                              nsIFrame* aKidFrame,
+                              const ReflowInput& aKidReflowInput,
+                              const mozilla::LogicalPoint& aKidPosition,
+                              const nsSize& aContainerSize,
+                              ReflowOutput& aKidDesiredSize,
+                              const nsRect& aOriginalKidRect,
+                              const nsRect& aOriginalKidInkOverflow) {
+  WritingMode wm = aReflowInput.mReflowInput.GetWritingMode();
+  bool isFirstReflow = aKidFrame->HasAnyStateBits(NS_FRAME_FIRST_REFLOW);
+
+  // Place and size the child
+  FinishReflowChild(aKidFrame, PresContext(), aKidDesiredSize, &aKidReflowInput,
+                    wm, aKidPosition, aContainerSize,
+                    ReflowChildFlags::ApplyRelativePositioning);
+
+  InvalidateTableFrame(aKidFrame, aOriginalKidRect, aOriginalKidInkOverflow,
+                       isFirstReflow);
+
+  aReflowInput.AdvanceBCoord(aKidDesiredSize.BSize(wm));
+}
+
+nsTableFrame::RowGroupArray nsTableFrame::OrderedRowGroups(
+    nsTableRowGroupFrame** aHead, nsTableRowGroupFrame** aFoot) const {
+  RowGroupArray children;
+  nsTableRowGroupFrame* head = nullptr;
+  nsTableRowGroupFrame* foot = nullptr;
+
+  nsIFrame* kidFrame = mFrames.FirstChild();
+  while (kidFrame) {
+    const nsStyleDisplay* kidDisplay = kidFrame->StyleDisplay();
+    auto* rowGroup = static_cast<nsTableRowGroupFrame*>(kidFrame);
+
+    switch (kidDisplay->DisplayInside()) {
+      case StyleDisplayInside::TableHeaderGroup:
+        if (head) {  // treat additional thead like tbody
+          children.AppendElement(rowGroup);
+        } else {
+          head = rowGroup;
+        }
+        break;
+      case StyleDisplayInside::TableFooterGroup:
+        if (foot) {  // treat additional tfoot like tbody
+          children.AppendElement(rowGroup);
+        } else {
+          foot = rowGroup;
+        }
+        break;
+      case StyleDisplayInside::TableRowGroup:
+        children.AppendElement(rowGroup);
+        break;
+      default:
+        MOZ_ASSERT_UNREACHABLE("How did this produce an nsTableRowGroupFrame?");
+        // Just ignore it
+        break;
+    }
+    // Get the next sibling but skip it if it's also the next-in-flow, since
+    // a next-in-flow will not be part of the current table.
+    while (kidFrame) {
+      nsIFrame* nif = kidFrame->GetNextInFlow();
+      kidFrame = kidFrame->GetNextSibling();
+      if (kidFrame != nif) {
+        break;
+      }
+    }
+  }
+
+  // put the thead first
+  if (head) {
+    children.InsertElementAt(0, head);
+  }
+  if (aHead) {
+    *aHead = head;
+  }
+  // put the tfoot after the last tbody
+  if (foot) {
+    children.AppendElement(foot);
+  }
+  if (aFoot) {
+    *aFoot = foot;
+  }
+
+  return children;
+}
+
+static bool IsRepeatable(nscoord aFrameBSize, nscoord aPageBSize) {
+  return aFrameBSize < (aPageBSize / 4);
+}
+
+nscoord nsTableFrame::SetupHeaderFooterChild(
+    const TableReflowInput& aReflowInput, nsTableRowGroupFrame* aFrame) {
+  nsPresContext* presContext = PresContext();
+  const WritingMode wm = GetWritingMode();
+  const nscoord pageBSize =
+      LogicalSize(wm, presContext->GetPageSize()).BSize(wm);
+
+  // Reflow the child with unconstrained block-size.
+  LogicalSize availSize = aReflowInput.AvailableSize();
+  availSize.BSize(wm) = NS_UNCONSTRAINEDSIZE;
+
+  const nsSize containerSize =
+      aReflowInput.mReflowInput.ComputedSizeAsContainerIfConstrained();
+  ReflowInput kidReflowInput(presContext, aReflowInput.mReflowInput, aFrame,
+                             availSize, Nothing(),
+                             ReflowInput::InitFlag::CallerWillInit);
+  InitChildReflowInput(kidReflowInput);
+  kidReflowInput.mFlags.mIsTopOfPage = true;
+  ReflowOutput desiredSize(aReflowInput.mReflowInput);
+  nsReflowStatus status;
+  ReflowChild(aFrame, presContext, desiredSize, kidReflowInput, wm,
+              LogicalPoint(wm, aReflowInput.mICoord, aReflowInput.mBCoord),
+              containerSize, ReflowChildFlags::Default, status);
+  // The child will be reflowed again "for real" so no need to place it now
+
+  aFrame->SetRepeatable(IsRepeatable(desiredSize.BSize(wm), pageBSize));
+  return desiredSize.BSize(wm);
+}
+
+void nsTableFrame::PlaceRepeatedFooter(TableReflowInput& aReflowInput,
+                                       nsTableRowGroupFrame* aTfoot,
+                                       nscoord aFooterBSize) {
+  nsPresContext* presContext = PresContext();
+  const WritingMode wm = GetWritingMode();
+  LogicalSize kidAvailSize = aReflowInput.AvailableSize();
+  kidAvailSize.BSize(wm) = aFooterBSize;
+
+  const nsSize containerSize =
+      aReflowInput.mReflowInput.ComputedSizeAsContainerIfConstrained();
+  ReflowInput footerReflowInput(presContext, aReflowInput.mReflowInput, aTfoot,
+                                kidAvailSize, Nothing(),
+                                ReflowInput::InitFlag::CallerWillInit);
+  InitChildReflowInput(footerReflowInput);
+  aReflowInput.AdvanceBCoord(GetRowSpacing(GetRowCount()));
+
+  nsRect origTfootRect = aTfoot->GetRect();
+  nsRect origTfootInkOverflow = aTfoot->InkOverflowRect();
+
+  nsReflowStatus footerStatus;
+  ReflowOutput desiredSize(aReflowInput.mReflowInput);
+  LogicalPoint kidPosition(wm, aReflowInput.mICoord, aReflowInput.mBCoord);
+  ReflowChild(aTfoot, presContext, desiredSize, footerReflowInput, wm,
+              kidPosition, containerSize, ReflowChildFlags::Default,
+              footerStatus);
+
+  PlaceChild(aReflowInput, aTfoot, footerReflowInput, kidPosition,
+             containerSize, desiredSize, origTfootRect, origTfootInkOverflow);
+}
+
+// Reflow the children based on the avail size and reason in aReflowInput
+void nsTableFrame::ReflowChildren(TableReflowInput& aReflowInput,
+                                  nsReflowStatus& aStatus,
+                                  nsIFrame*& aLastChildReflowed,
+                                  OverflowAreas& aOverflowAreas) {
+  aStatus.Reset();
+  aLastChildReflowed = nullptr;
+
+  nsIFrame* prevKidFrame = nullptr;
+  WritingMode wm = aReflowInput.mReflowInput.GetWritingMode();
+  NS_WARNING_ASSERTION(
+      wm.IsVertical() ||
+          NS_UNCONSTRAINEDSIZE != aReflowInput.mReflowInput.ComputedWidth(),
+      "shouldn't have unconstrained width in horizontal mode");
+  nsSize containerSize =
+      aReflowInput.mReflowInput.ComputedSizeAsContainerIfConstrained();
+
+  nsPresContext* presContext = PresContext();
+  // nsTableFrame is not able to pull back children from its next-in-flow, per
+  // bug 1772383.  So even under paginated contexts, tables should not fragment
+  // if they are inside of (i.e. potentially being fragmented by) a column-set
+  // frame.  (This is indicated by the "mTableIsSplittable" flag.)
+  bool isPaginated =
+      presContext->IsPaginated() &&
+      aReflowInput.mReflowInput.AvailableBSize() != NS_UNCONSTRAINEDSIZE &&
+      aReflowInput.mReflowInput.mFlags.mTableIsSplittable;
+
+  // Tables currently (though we ought to fix this) only fragment in
+  // paginated contexts, not in multicolumn contexts.  (See bug 888257.)
+  // This is partly because they don't correctly handle incremental
+  // layout when paginated.
+  //
+  // Since we propagate NS_FRAME_IS_DIRTY from parent to child at the
+  // start of the parent's reflow (behavior that's new as of bug
+  // 1308876), we can do things that are effectively incremental reflow
+  // during paginated layout.  Since the table code doesn't handle this
+  // correctly, we need to set the flag that says to reflow everything
+  // within the table structure.
+  if (presContext->IsPaginated()) {
+    SetGeometryDirty();
+  }
+
+  aOverflowAreas.Clear();
+
+  bool reflowAllKids = aReflowInput.mReflowInput.ShouldReflowAllKids() ||
+                       mBits.mResizedColumns || IsGeometryDirty() ||
+                       NeedToCollapse();
+
+  nsTableRowGroupFrame* thead = nullptr;
+  nsTableRowGroupFrame* tfoot = nullptr;
+  RowGroupArray rowGroups = OrderedRowGroups(&thead, &tfoot);
+  bool pageBreak = false;
+  nscoord footerBSize = 0;
+
+  // Determine the repeatablility of headers and footers, and also the desired
+  // height of any repeatable footer.
+  // The repeatability of headers on continued tables is handled
+  // when they are created in nsCSSFrameConstructor::CreateContinuingTableFrame.
+  // We handle the repeatability of footers again here because we need to
+  // determine the footer's height anyway. We could perhaps optimize by
+  // using the footer's prev-in-flow's height instead of reflowing it again,
+  // but there's no real need.
+  if (isPaginated) {
+    bool reorder = false;
+    if (thead && !GetPrevInFlow()) {
+      reorder = thead->GetNextInFlow();
+      SetupHeaderFooterChild(aReflowInput, thead);
+    }
+    if (tfoot) {
+      reorder = reorder || tfoot->GetNextInFlow();
+      footerBSize = SetupHeaderFooterChild(aReflowInput, tfoot);
+    }
+    if (reorder) {
+      // Reorder row groups - the reflow may have changed the nextinflows.
+      rowGroups = OrderedRowGroups(&thead, &tfoot);
+    }
+  }
+  bool allowRepeatedFooter = false;
+  for (size_t childX = 0; childX < rowGroups.Length(); childX++) {
+    nsTableRowGroupFrame* kidFrame = rowGroups[childX];
+    const nscoord rowSpacing =
+        GetRowSpacing(kidFrame->GetStartRowIndex() + kidFrame->GetRowCount());
+    // See if we should only reflow the dirty child frames
+    if (reflowAllKids || kidFrame->IsSubtreeDirty() ||
+        (aReflowInput.mReflowInput.mFlags.mSpecialBSizeReflow &&
+         (isPaginated ||
+          kidFrame->HasAnyStateBits(NS_FRAME_CONTAINS_RELATIVE_BSIZE)))) {
+      // A helper to place a repeated footer if allowed, or set it as
+      // non-repeatable.
+      auto MaybePlaceRepeatedFooter = [&]() {
+        if (allowRepeatedFooter) {
+          PlaceRepeatedFooter(aReflowInput, tfoot, footerBSize);
+        } else if (tfoot && tfoot->IsRepeatable()) {
+          tfoot->SetRepeatable(false);
+        }
+      };
+
+      if (pageBreak) {
+        MaybePlaceRepeatedFooter();
+        PushChildrenToOverflow(rowGroups, childX);
+        aStatus.Reset();
+        aStatus.SetIncomplete();
+        break;
+      }
+
+      LogicalSize kidAvailSize = aReflowInput.AvailableSize();
+      allowRepeatedFooter = false;
+
+      // If the child is a tbody in paginated mode, reduce the available
+      // block-size by a repeated footer.
+      if (isPaginated && (NS_UNCONSTRAINEDSIZE != kidAvailSize.BSize(wm))) {
+        if (kidFrame != thead && kidFrame != tfoot && tfoot &&
+            tfoot->IsRepeatable()) {
+          // the child is a tbody and there is a repeatable footer
+          NS_ASSERTION(tfoot == rowGroups[rowGroups.Length() - 1],
+                       "Missing footer!");
+          if (footerBSize + rowSpacing < kidAvailSize.BSize(wm)) {
+            allowRepeatedFooter = true;
+            kidAvailSize.BSize(wm) -= footerBSize + rowSpacing;
+          }
+        }
+      }
+
+      nsRect oldKidRect = kidFrame->GetRect();
+      nsRect oldKidInkOverflow = kidFrame->InkOverflowRect();
+
+      ReflowOutput desiredSize(aReflowInput.mReflowInput);
+
+      // Reflow the child into the available space
+      ReflowInput kidReflowInput(presContext, aReflowInput.mReflowInput,
+                                 kidFrame, kidAvailSize, Nothing(),
+                                 ReflowInput::InitFlag::CallerWillInit);
+      InitChildReflowInput(kidReflowInput);
+
+      // If this isn't the first row group, and the previous row group has a
+      // nonzero BEnd, then we can't be at the top of the page.
+      // We ignore a repeated head row group in this check to avoid causing
+      // infinite loops in some circumstances - see bug 344883.
+      if (childX > ((thead && IsRepeatedFrame(thead)) ? 1u : 0u) &&
+          (rowGroups[childX - 1]
+               ->GetLogicalNormalRect(wm, containerSize)
+               .BEnd(wm) > 0)) {
+        kidReflowInput.mFlags.mIsTopOfPage = false;
+      }
+      aReflowInput.AdvanceBCoord(rowSpacing);
+      // record the presence of a next in flow, it might get destroyed so we
+      // need to reorder the row group array
+      const bool reorder = kidFrame->GetNextInFlow();
+
+      LogicalPoint kidPosition(wm, aReflowInput.mICoord, aReflowInput.mBCoord);
+      aStatus.Reset();
+      ReflowChild(kidFrame, presContext, desiredSize, kidReflowInput, wm,
+                  kidPosition, containerSize, ReflowChildFlags::Default,
+                  aStatus);
+
+      if (reorder) {
+        // Reorder row groups - the reflow may have changed the nextinflows.
+        rowGroups = OrderedRowGroups(&thead, &tfoot);
+        childX = rowGroups.IndexOf(kidFrame);
+        MOZ_ASSERT(childX != RowGroupArray::NoIndex,
+                   "kidFrame should still be in rowGroups!");
+      }
+      if (isPaginated && !aStatus.IsFullyComplete() &&
+          ShouldAvoidBreakInside(aReflowInput.mReflowInput)) {
+        aStatus.SetInlineLineBreakBeforeAndReset();
+        break;
+      }
+      // see if the rowgroup did not fit on this page might be pushed on
+      // the next page
+      if (isPaginated &&
+          (aStatus.IsInlineBreakBefore() ||
+           (aStatus.IsComplete() &&
+            (kidReflowInput.AvailableBSize() != NS_UNCONSTRAINEDSIZE) &&
+            kidReflowInput.AvailableBSize() < desiredSize.BSize(wm)))) {
+        if (ShouldAvoidBreakInside(aReflowInput.mReflowInput)) {
+          aStatus.SetInlineLineBreakBeforeAndReset();
+          break;
+        }
+        // if we are on top of the page place with dataloss
+        if (kidReflowInput.mFlags.mIsTopOfPage) {
+          if (childX + 1 < rowGroups.Length()) {
+            PlaceChild(aReflowInput, kidFrame, kidReflowInput, kidPosition,
+                       containerSize, desiredSize, oldKidRect,
+                       oldKidInkOverflow);
+            MaybePlaceRepeatedFooter();
+            aStatus.Reset();
+            aStatus.SetIncomplete();
+            PushChildrenToOverflow(rowGroups, childX + 1);
+            aLastChildReflowed = kidFrame;
+            break;
+          }
+        } else {  // we are not on top, push this rowgroup onto the next page
+          if (prevKidFrame) {  // we had a rowgroup before so push this
+            MaybePlaceRepeatedFooter();
+            aStatus.Reset();
+            aStatus.SetIncomplete();
+            PushChildrenToOverflow(rowGroups, childX);
+            aLastChildReflowed = prevKidFrame;
+            break;
+          } else {  // we can't push so lets make clear how much space we need
+            PlaceChild(aReflowInput, kidFrame, kidReflowInput, kidPosition,
+                       containerSize, desiredSize, oldKidRect,
+                       oldKidInkOverflow);
+            MaybePlaceRepeatedFooter();
+            aLastChildReflowed = allowRepeatedFooter ? tfoot : kidFrame;
+            break;
+          }
+        }
+      }
+
+      aLastChildReflowed = kidFrame;
+
+      pageBreak = false;
+      // see if there is a page break after this row group or before the next
+      // one
+      if (aStatus.IsComplete() && isPaginated &&
+          (kidReflowInput.AvailableBSize() != NS_UNCONSTRAINEDSIZE)) {
+        nsIFrame* nextKid =
+            (childX + 1 < rowGroups.Length()) ? rowGroups[childX + 1] : nullptr;
+        pageBreak = PageBreakAfter(kidFrame, nextKid);
+      }
+
+      // Place the child
+      PlaceChild(aReflowInput, kidFrame, kidReflowInput, kidPosition,
+                 containerSize, desiredSize, oldKidRect, oldKidInkOverflow);
+
+      // Remember where we just were in case we end up pushing children
+      prevKidFrame = kidFrame;
+
+      MOZ_ASSERT(!aStatus.IsIncomplete() || isPaginated,
+                 "Table contents should only fragment in paginated contexts");
+
+      // Special handling for incomplete children
+      if (isPaginated && aStatus.IsIncomplete()) {
+        nsIFrame* kidNextInFlow = kidFrame->GetNextInFlow();
+        if (!kidNextInFlow) {
+          // The child doesn't have a next-in-flow so create a continuing
+          // frame. This hooks the child into the flow
+          kidNextInFlow =
+              PresShell()->FrameConstructor()->CreateContinuingFrame(kidFrame,
+                                                                     this);
+
+          // Insert the kid's new next-in-flow into our sibling list...
+          mFrames.InsertFrame(nullptr, kidFrame, kidNextInFlow);
+          // and in rowGroups after childX so that it will get pushed below.
+          rowGroups.InsertElementAt(
+              childX + 1, static_cast<nsTableRowGroupFrame*>(kidNextInFlow));
+        } else if (kidNextInFlow == kidFrame->GetNextSibling()) {
+          // OrderedRowGroups excludes NIFs in the child list from 'rowGroups'
+          // so we deal with that here to make sure they get pushed.
+          MOZ_ASSERT(!rowGroups.Contains(kidNextInFlow),
+                     "OrderedRowGroups must not put our NIF in 'rowGroups'");
+          rowGroups.InsertElementAt(
+              childX + 1, static_cast<nsTableRowGroupFrame*>(kidNextInFlow));
+        }
+
+        // We've used up all of our available space so push the remaining
+        // children.
+        MaybePlaceRepeatedFooter();
+        if (kidFrame->GetNextSibling()) {
+          PushChildrenToOverflow(rowGroups, childX + 1);
+        }
+        break;
+      }
+    } else {  // it isn't being reflowed
+      aReflowInput.AdvanceBCoord(rowSpacing);
+      const LogicalRect kidRect =
+          kidFrame->GetLogicalNormalRect(wm, containerSize);
+      if (kidRect.BStart(wm) != aReflowInput.mBCoord) {
+        // invalidate the old position
+        kidFrame->InvalidateFrameSubtree();
+        // move to the new position
+        kidFrame->MovePositionBy(
+            wm, LogicalPoint(wm, 0, aReflowInput.mBCoord - kidRect.BStart(wm)));
+        RePositionViews(kidFrame);
+        // invalidate the new position
+        kidFrame->InvalidateFrameSubtree();
+      }
+
+      aReflowInput.AdvanceBCoord(kidRect.BSize(wm));
+    }
+  }
+
+  // We've now propagated the column resizes and geometry changes to all
+  // the children.
+  mBits.mResizedColumns = false;
+  ClearGeometryDirty();
+
+  // nsTableFrame does not pull children from its next-in-flow (bug 1772383).
+  // This is generally fine, since tables only fragment for printing
+  // (bug 888257) where incremental-reflow is impossible, and so children don't
+  // usually dynamically move back and forth between continuations. However,
+  // there are edge cases even with printing where nsTableFrame:
+  // (1) Generates a continuation and passes children to it,
+  // (2) Receives another call to Reflow, during which it
+  // (3) Successfully lays out its remaining children.
+  // If the completed status flows up as-is, the continuation will be destroyed.
+  // To avoid that, we return an incomplete status if the continuation contains
+  // any child that is not a repeated frame.
+  auto hasNextInFlowThatMustBePreserved = [this, isPaginated]() -> bool {
+    if (!isPaginated) {
+      return false;
+    }
+    auto* nextInFlow = static_cast<nsTableFrame*>(GetNextInFlow());
+    if (!nextInFlow) {
+      return false;
+    }
+    for (nsIFrame* kidFrame : nextInFlow->mFrames) {
+      if (!IsRepeatedFrame(kidFrame)) {
+        return true;
+      }
+    }
+    return false;
+  };
+  if (aStatus.IsComplete() && hasNextInFlowThatMustBePreserved()) {
+    aStatus.SetIncomplete();
+  }
+}
+
+void nsTableFrame::ReflowColGroups(gfxContext* aRenderingContext) {
+  if (!GetPrevInFlow() && !HaveReflowedColGroups()) {
+    const WritingMode wm = GetWritingMode();
+    nsPresContext* presContext = PresContext();
+    for (nsIFrame* kidFrame : mColGroups) {
+      if (kidFrame->IsSubtreeDirty()) {
+        // The column groups don't care about dimensions or reflow inputs.
+        ReflowOutput kidSize(wm);
+        ReflowInput kidReflowInput(presContext, kidFrame, aRenderingContext,
+                                   LogicalSize(kidFrame->GetWritingMode()));
+        nsReflowStatus cgStatus;
+        const LogicalPoint dummyPos(wm);
+        const nsSize dummyContainerSize;
+        ReflowChild(kidFrame, presContext, kidSize, kidReflowInput, wm,
+                    dummyPos, dummyContainerSize, ReflowChildFlags::Default,
+                    cgStatus);
+        FinishReflowChild(kidFrame, presContext, kidSize, &kidReflowInput, wm,
+                          dummyPos, dummyContainerSize,
+                          ReflowChildFlags::Default);
+      }
+    }
+    SetHaveReflowedColGroups(true);
+  }
+}
+
+nscoord nsTableFrame::CalcDesiredBSize(const ReflowInput& aReflowInput,
+                                       const LogicalMargin& aBorderPadding) {
+  WritingMode wm = aReflowInput.GetWritingMode();
+
+  // get the natural bsize based on the last child's (row group) rect
+  RowGroupArray rowGroups = OrderedRowGroups();
+  if (rowGroups.IsEmpty()) {
+    if (eCompatibility_NavQuirks == PresContext()->CompatibilityMode()) {
+      // empty tables should not have a size in quirks mode
+      return 0;
+    }
+    return CalcBorderBoxBSize(aReflowInput, aBorderPadding,
+                              aBorderPadding.BStartEnd(wm));
+  }
+
+  nsTableCellMap* cellMap = GetCellMap();
+  MOZ_ASSERT(cellMap);
+  int32_t rowCount = cellMap->GetRowCount();
+  int32_t colCount = cellMap->GetColCount();
+  nscoord desiredBSize = aBorderPadding.BStartEnd(wm);
+  if (rowCount > 0 && colCount > 0) {
+    desiredBSize += GetRowSpacing(-1);
+    for (uint32_t rgIdx = 0; rgIdx < rowGroups.Length(); rgIdx++) {
+      desiredBSize += rowGroups[rgIdx]->BSize(wm) +
+                      GetRowSpacing(rowGroups[rgIdx]->GetRowCount() +
+                                    rowGroups[rgIdx]->GetStartRowIndex());
+    }
+  }
+
+  // see if a specified table bsize requires dividing additional space to rows
+  if (!GetPrevInFlow()) {
+    nscoord bSize =
+        CalcBorderBoxBSize(aReflowInput, aBorderPadding, desiredBSize);
+    if (bSize > desiredBSize) {
+      // proportionately distribute the excess bsize to unconstrained rows in
+      // each unconstrained row group.
+      DistributeBSizeToRows(aReflowInput, bSize - desiredBSize);
+      return bSize;
+    }
+    // Tables don't shrink below their intrinsic size, apparently, even when
+    // constrained by stuff like flex / grid or what not.
+    return desiredBSize;
+  }
+
+  // FIXME(emilio): Is this right? This only affects fragmented tables...
+  return desiredBSize;
+}
+
+static void ResizeCells(nsTableFrame& aTableFrame) {
+  nsTableFrame::RowGroupArray rowGroups = aTableFrame.OrderedRowGroups();
+  WritingMode wm = aTableFrame.GetWritingMode();
+  ReflowOutput tableDesiredSize(wm);
+  tableDesiredSize.SetSize(wm, aTableFrame.GetLogicalSize(wm));
+  tableDesiredSize.SetOverflowAreasToDesiredBounds();
+
+  for (uint32_t rgIdx = 0; rgIdx < rowGroups.Length(); rgIdx++) {
+    nsTableRowGroupFrame* rgFrame = rowGroups[rgIdx];
+
+    ReflowOutput groupDesiredSize(wm);
+    groupDesiredSize.SetSize(wm, rgFrame->GetLogicalSize(wm));
+    groupDesiredSize.SetOverflowAreasToDesiredBounds();
+
+    nsTableRowFrame* rowFrame = rgFrame->GetFirstRow();
+    while (rowFrame) {
+      rowFrame->DidResize();
+      rgFrame->ConsiderChildOverflow(groupDesiredSize.mOverflowAreas, rowFrame);
+      rowFrame = rowFrame->GetNextRow();
+    }
+    rgFrame->FinishAndStoreOverflow(&groupDesiredSize);
+    tableDesiredSize.mOverflowAreas.UnionWith(groupDesiredSize.mOverflowAreas +
+                                              rgFrame->GetPosition());
+  }
+  aTableFrame.FinishAndStoreOverflow(&tableDesiredSize);
+}
+
+void nsTableFrame::DistributeBSizeToRows(const ReflowInput& aReflowInput,
+                                         nscoord aAmount) {
+  WritingMode wm = aReflowInput.GetWritingMode();
+  LogicalMargin borderPadding = aReflowInput.ComputedLogicalBorderPadding(wm);
+
+  nsSize containerSize = aReflowInput.ComputedSizeAsContainerIfConstrained();
+
+  RowGroupArray rowGroups = OrderedRowGroups();
+
+  nscoord amountUsed = 0;
+  // distribute space to each pct bsize row whose row group doesn't have a
+  // computed bsize, and base the pct on the table bsize. If the row group had a
+  // computed bsize, then this was already done in
+  // nsTableRowGroupFrame::CalculateRowBSizes
+  nscoord pctBasis =
+      aReflowInput.ComputedBSize() - GetRowSpacing(-1, GetRowCount());
+  nscoord bOriginRG = borderPadding.BStart(wm) + GetRowSpacing(0);
+  nscoord bEndRG = bOriginRG;
+  uint32_t rgIdx;
+  for (rgIdx = 0; rgIdx < rowGroups.Length(); rgIdx++) {
+    nsTableRowGroupFrame* rgFrame = rowGroups[rgIdx];
+    nscoord amountUsedByRG = 0;
+    nscoord bOriginRow = 0;
+    const LogicalRect rgNormalRect =
+        rgFrame->GetLogicalNormalRect(wm, containerSize);
+    if (!rgFrame->HasStyleBSize()) {
+      nsTableRowFrame* rowFrame = rgFrame->GetFirstRow();
+      while (rowFrame) {
+        // We don't know the final width of the rowGroupFrame yet, so use 0,0
+        // as a dummy containerSize here; we'll adjust the row positions at
+        // the end, after the rowGroup size is finalized.
+        const nsSize dummyContainerSize;
+        const LogicalRect rowNormalRect =
+            rowFrame->GetLogicalNormalRect(wm, dummyContainerSize);
+        const nscoord rowSpacing = GetRowSpacing(rowFrame->GetRowIndex());
+        if ((amountUsed < aAmount) && rowFrame->HasPctBSize()) {
+          nscoord pctBSize = rowFrame->GetInitialBSize(pctBasis);
+          nscoord amountForRow = std::min(aAmount - amountUsed,
+                                          pctBSize - rowNormalRect.BSize(wm));
+          if (amountForRow > 0) {
+            // XXXbz we don't need to move the row's b-position to bOriginRow?
+            nsRect origRowRect = rowFrame->GetRect();
+            nscoord newRowBSize = rowNormalRect.BSize(wm) + amountForRow;
+            rowFrame->SetSize(
+                wm, LogicalSize(wm, rowNormalRect.ISize(wm), newRowBSize));
+            bOriginRow += newRowBSize + rowSpacing;
+            bEndRG += newRowBSize + rowSpacing;
+            amountUsed += amountForRow;
+            amountUsedByRG += amountForRow;
+            // rowFrame->DidResize();
+            nsTableFrame::RePositionViews(rowFrame);
+
+            rgFrame->InvalidateFrameWithRect(origRowRect);
+            rgFrame->InvalidateFrame();
+          }
+        } else {
+          if (amountUsed > 0 && bOriginRow != rowNormalRect.BStart(wm) &&
+              !HasAnyStateBits(NS_FRAME_FIRST_REFLOW)) {
+            rowFrame->InvalidateFrameSubtree();
+            rowFrame->MovePositionBy(
+                wm, LogicalPoint(wm, 0, bOriginRow - rowNormalRect.BStart(wm)));
+            nsTableFrame::RePositionViews(rowFrame);
+            rowFrame->InvalidateFrameSubtree();
+          }
+          bOriginRow += rowNormalRect.BSize(wm) + rowSpacing;
+          bEndRG += rowNormalRect.BSize(wm) + rowSpacing;
+        }
+        rowFrame = rowFrame->GetNextRow();
+      }
+      if (amountUsed > 0) {
+        if (rgNormalRect.BStart(wm) != bOriginRG) {
+          rgFrame->InvalidateFrameSubtree();
+        }
+
+        nsRect origRgNormalRect = rgFrame->GetRect();
+        nsRect origRgInkOverflow = rgFrame->InkOverflowRect();
+
+        rgFrame->MovePositionBy(
+            wm, LogicalPoint(wm, 0, bOriginRG - rgNormalRect.BStart(wm)));
+        rgFrame->SetSize(wm,
+                         LogicalSize(wm, rgNormalRect.ISize(wm),
+                                     rgNormalRect.BSize(wm) + amountUsedByRG));
+
+        nsTableFrame::InvalidateTableFrame(rgFrame, origRgNormalRect,
+                                           origRgInkOverflow, false);
+      }
+    } else if (amountUsed > 0 && bOriginRG != rgNormalRect.BStart(wm)) {
+      rgFrame->InvalidateFrameSubtree();
+      rgFrame->MovePositionBy(
+          wm, LogicalPoint(wm, 0, bOriginRG - rgNormalRect.BStart(wm)));
+      // Make sure child views are properly positioned
+      nsTableFrame::RePositionViews(rgFrame);
+      rgFrame->InvalidateFrameSubtree();
+    }
+    bOriginRG = bEndRG;
+  }
+
+  if (amountUsed >= aAmount) {
+    ResizeCells(*this);
+    return;
+  }
+
+  // get the first row without a style bsize where its row group has an
+  // unconstrained bsize
+  nsTableRowGroupFrame* firstUnStyledRG = nullptr;
+  nsTableRowFrame* firstUnStyledRow = nullptr;
+  for (rgIdx = 0; rgIdx < rowGroups.Length() && !firstUnStyledRG; rgIdx++) {
+    nsTableRowGroupFrame* rgFrame = rowGroups[rgIdx];
+    if (!rgFrame->HasStyleBSize()) {
+      nsTableRowFrame* rowFrame = rgFrame->GetFirstRow();
+      while (rowFrame) {
+        if (!rowFrame->HasStyleBSize()) {
+          firstUnStyledRG = rgFrame;
+          firstUnStyledRow = rowFrame;
+          break;
+        }
+        rowFrame = rowFrame->GetNextRow();
+      }
+    }
+  }
+
+  nsTableRowFrame* lastEligibleRow = nullptr;
+  // Accumulate the correct divisor. This will be the total bsize of all
+  // unstyled rows inside unstyled row groups, unless there are none, in which
+  // case, it will be number of all rows. If the unstyled rows don't have a
+  // bsize, divide the space equally among them.
+  nscoord divisor = 0;
+  int32_t eligibleRows = 0;
+  bool expandEmptyRows = false;
+
+  if (!firstUnStyledRow) {
+    // there is no unstyled row
+    divisor = GetRowCount();
+  } else {
+    for (rgIdx = 0; rgIdx < rowGroups.Length(); rgIdx++) {
+      nsTableRowGroupFrame* rgFrame = rowGroups[rgIdx];
+      if (!firstUnStyledRG || !rgFrame->HasStyleBSize()) {
+        nsTableRowFrame* rowFrame = rgFrame->GetFirstRow();
+        while (rowFrame) {
+          if (!firstUnStyledRG || !rowFrame->HasStyleBSize()) {
+            NS_ASSERTION(rowFrame->BSize(wm) >= 0,
+                         "negative row frame block-size");
+            divisor += rowFrame->BSize(wm);
+            eligibleRows++;
+            lastEligibleRow = rowFrame;
+          }
+          rowFrame = rowFrame->GetNextRow();
+        }
+      }
+    }
+    if (divisor <= 0) {
+      if (eligibleRows > 0) {
+        expandEmptyRows = true;
+      } else {
+        NS_ERROR("invalid divisor");
+        return;
+      }
+    }
+  }
+  // allocate the extra bsize to the unstyled row groups and rows
+  nscoord bSizeToDistribute = aAmount - amountUsed;
+  bOriginRG = borderPadding.BStart(wm) + GetRowSpacing(-1);
+  bEndRG = bOriginRG;
+  for (rgIdx = 0; rgIdx < rowGroups.Length(); rgIdx++) {
+    nsTableRowGroupFrame* rgFrame = rowGroups[rgIdx];
+    nscoord amountUsedByRG = 0;
+    nscoord bOriginRow = 0;
+    const LogicalRect rgNormalRect =
+        rgFrame->GetLogicalNormalRect(wm, containerSize);
+    nsRect rgInkOverflow = rgFrame->InkOverflowRect();
+    // see if there is an eligible row group or we distribute to all rows
+    if (!firstUnStyledRG || !rgFrame->HasStyleBSize() || !eligibleRows) {
+      for (nsTableRowFrame* rowFrame = rgFrame->GetFirstRow(); rowFrame;
+           rowFrame = rowFrame->GetNextRow()) {
+        const nscoord rowSpacing = GetRowSpacing(rowFrame->GetRowIndex());
+        // We don't know the final width of the rowGroupFrame yet, so use 0,0
+        // as a dummy containerSize here; we'll adjust the row positions at
+        // the end, after the rowGroup size is finalized.
+        const nsSize dummyContainerSize;
+        const LogicalRect rowNormalRect =
+            rowFrame->GetLogicalNormalRect(wm, dummyContainerSize);
+        nsRect rowInkOverflow = rowFrame->InkOverflowRect();
+        // see if there is an eligible row or we distribute to all rows
+        if (!firstUnStyledRow || !rowFrame->HasStyleBSize() || !eligibleRows) {
+          float ratio;
+          if (eligibleRows) {
+            if (!expandEmptyRows) {
+              // The amount of additional space each row gets is proportional
+              // to its bsize
+              ratio = float(rowNormalRect.BSize(wm)) / float(divisor);
+            } else {
+              // empty rows get all the same additional space
+              ratio = 1.0f / float(eligibleRows);
+            }
+          } else {
+            // all rows get the same additional space
+            ratio = 1.0f / float(divisor);
+          }
+          // give rows their additional space, except for the last row which
+          // gets the remainder
+          nscoord amountForRow =
+              (rowFrame == lastEligibleRow)
+                  ? aAmount - amountUsed
+                  : NSToCoordRound(((float)(bSizeToDistribute)) * ratio);
+          amountForRow = std::min(amountForRow, aAmount - amountUsed);
+
+          if (bOriginRow != rowNormalRect.BStart(wm)) {
+            rowFrame->InvalidateFrameSubtree();
+          }
+
+          // update the row bsize
+          nsRect origRowRect = rowFrame->GetRect();
+          nscoord newRowBSize = rowNormalRect.BSize(wm) + amountForRow;
+          rowFrame->MovePositionBy(
+              wm, LogicalPoint(wm, 0, bOriginRow - rowNormalRect.BStart(wm)));
+          rowFrame->SetSize(
+              wm, LogicalSize(wm, rowNormalRect.ISize(wm), newRowBSize));
+
+          bOriginRow += newRowBSize + rowSpacing;
+          bEndRG += newRowBSize + rowSpacing;
+
+          amountUsed += amountForRow;
+          amountUsedByRG += amountForRow;
+          NS_ASSERTION((amountUsed <= aAmount), "invalid row allocation");
+          // rowFrame->DidResize();
+          nsTableFrame::RePositionViews(rowFrame);
+
+          nsTableFrame::InvalidateTableFrame(rowFrame, origRowRect,
+                                             rowInkOverflow, false);
+        } else {
+          if (amountUsed > 0 && bOriginRow != rowNormalRect.BStart(wm)) {
+            rowFrame->InvalidateFrameSubtree();
+            rowFrame->MovePositionBy(
+                wm, LogicalPoint(wm, 0, bOriginRow - rowNormalRect.BStart(wm)));
+            nsTableFrame::RePositionViews(rowFrame);
+            rowFrame->InvalidateFrameSubtree();
+          }
+          bOriginRow += rowNormalRect.BSize(wm) + rowSpacing;
+          bEndRG += rowNormalRect.BSize(wm) + rowSpacing;
+        }
+      }
+
+      if (amountUsed > 0) {
+        if (rgNormalRect.BStart(wm) != bOriginRG) {
+          rgFrame->InvalidateFrameSubtree();
+        }
+
+        nsRect origRgNormalRect = rgFrame->GetRect();
+        rgFrame->MovePositionBy(
+            wm, LogicalPoint(wm, 0, bOriginRG - rgNormalRect.BStart(wm)));
+        rgFrame->SetSize(wm,
+                         LogicalSize(wm, rgNormalRect.ISize(wm),
+                                     rgNormalRect.BSize(wm) + amountUsedByRG));
+
+        nsTableFrame::InvalidateTableFrame(rgFrame, origRgNormalRect,
+                                           rgInkOverflow, false);
+      }
+
+      // For vertical-rl mode, we needed to position the rows relative to the
+      // right-hand (block-start) side of the group; but we couldn't do that
+      // above, as we didn't know the rowGroupFrame's final block size yet.
+      // So we used a dummyContainerSize of 0,0 earlier, placing the rows to
+      // the left of the rowGroupFrame's (physical) origin. Now we move them
+      // all rightwards by its final width.
+      if (wm.IsVerticalRL()) {
+        nscoord rgWidth = rgFrame->GetSize().width;
+        for (nsTableRowFrame* rowFrame = rgFrame->GetFirstRow(); rowFrame;
+             rowFrame = rowFrame->GetNextRow()) {
+          rowFrame->InvalidateFrameSubtree();
+          rowFrame->MovePositionBy(nsPoint(rgWidth, 0));
+          nsTableFrame::RePositionViews(rowFrame);
+          rowFrame->InvalidateFrameSubtree();
+        }
+      }
+    } else if (amountUsed > 0 && bOriginRG != rgNormalRect.BStart(wm)) {
+      rgFrame->InvalidateFrameSubtree();
+      rgFrame->MovePositionBy(
+          wm, LogicalPoint(wm, 0, bOriginRG - rgNormalRect.BStart(wm)));
+      // Make sure child views are properly positioned
+      nsTableFrame::RePositionViews(rgFrame);
+      rgFrame->InvalidateFrameSubtree();
+    }
+    bOriginRG = bEndRG;
+  }
+
+  ResizeCells(*this);
+}
+
+nscoord nsTableFrame::GetColumnISizeFromFirstInFlow(int32_t aColIndex) {
+  MOZ_ASSERT(this == FirstInFlow());
+  nsTableColFrame* colFrame = GetColFrame(aColIndex);
+  return colFrame ? colFrame->GetFinalISize() : 0;
+}
+
+nscoord nsTableFrame::GetColSpacing() {
+  if (IsBorderCollapse()) return 0;
+
+  return StyleTableBorder()->mBorderSpacingCol;
+}
+
+// XXX: could cache this.  But be sure to check style changes if you do!
+nscoord nsTableFrame::GetColSpacing(int32_t aColIndex) {
+  NS_ASSERTION(aColIndex >= -1 && aColIndex <= GetColCount(),
+               "Column index exceeds the bounds of the table");
+  // Index is irrelevant for ordinary tables.  We check that it falls within
+  // appropriate bounds to increase confidence of correctness in situations
+  // where it does matter.
+  return GetColSpacing();
+}
+
+nscoord nsTableFrame::GetColSpacing(int32_t aStartColIndex,
+                                    int32_t aEndColIndex) {
+  NS_ASSERTION(aStartColIndex >= -1 && aStartColIndex <= GetColCount(),
+               "Start column index exceeds the bounds of the table");
+  NS_ASSERTION(aEndColIndex >= -1 && aEndColIndex <= GetColCount(),
+               "End column index exceeds the bounds of the table");
+  NS_ASSERTION(aStartColIndex <= aEndColIndex,
+               "End index must not be less than start index");
+  // Only one possible value so just multiply it out. Tables where index
+  // matters will override this function
+  return GetColSpacing() * (aEndColIndex - aStartColIndex);
+}
+
+nscoord nsTableFrame::GetRowSpacing() {
+  if (IsBorderCollapse()) return 0;
+
+  return StyleTableBorder()->mBorderSpacingRow;
+}
+
+// XXX: could cache this. But be sure to check style changes if you do!
+nscoord nsTableFrame::GetRowSpacing(int32_t aRowIndex) {
+  NS_ASSERTION(aRowIndex >= -1 && aRowIndex <= GetRowCount(),
+               "Row index exceeds the bounds of the table");
+  // Index is irrelevant for ordinary tables.  We check that it falls within
+  // appropriate bounds to increase confidence of correctness in situations
+  // where it does matter.
+  return GetRowSpacing();
+}
+
+nscoord nsTableFrame::GetRowSpacing(int32_t aStartRowIndex,
+                                    int32_t aEndRowIndex) {
+  NS_ASSERTION(aStartRowIndex >= -1 && aStartRowIndex <= GetRowCount(),
+               "Start row index exceeds the bounds of the table");
+  NS_ASSERTION(aEndRowIndex >= -1 && aEndRowIndex <= GetRowCount(),
+               "End row index exceeds the bounds of the table");
+  NS_ASSERTION(aStartRowIndex <= aEndRowIndex,
+               "End index must not be less than start index");
+  // Only one possible value so just multiply it out. Tables where index
+  // matters will override this function
+  return GetRowSpacing() * (aEndRowIndex - aStartRowIndex);
+}
+
+nscoord nsTableFrame::SynthesizeFallbackBaseline(
+    mozilla::WritingMode aWM, BaselineSharingGroup aBaselineGroup) const {
+  if (aBaselineGroup == BaselineSharingGroup::Last) {
+    return 0;
+  }
+  return BSize(aWM);
+}
+
+/* virtual */
+Maybe<nscoord> nsTableFrame::GetNaturalBaselineBOffset(
+    WritingMode aWM, BaselineSharingGroup aBaselineGroup,
+    BaselineExportContext) const {
+  if (StyleDisplay()->IsContainLayout()) {
+    return Nothing{};
+  }
+
+  RowGroupArray orderedRowGroups = OrderedRowGroups();
+  // XXX not sure if this should be the size of the containing block instead.
+  nsSize containerSize = mRect.Size();
+  auto TableBaseline = [aWM, containerSize](
+                           nsTableRowGroupFrame* aRowGroup,
+                           nsTableRowFrame* aRow) -> Maybe<nscoord> {
+    const nscoord rgBStart =
+        aRowGroup->GetLogicalNormalRect(aWM, containerSize).BStart(aWM);
+    const nscoord rowBStart =
+        aRow->GetLogicalNormalRect(aWM, aRowGroup->GetSize()).BStart(aWM);
+    return aRow->GetRowBaseline(aWM).map(
+        [rgBStart, rowBStart](nscoord aBaseline) {
+          return rgBStart + rowBStart + aBaseline;
+        });
+  };
+  if (aBaselineGroup == BaselineSharingGroup::First) {
+    for (uint32_t rgIndex = 0; rgIndex < orderedRowGroups.Length(); rgIndex++) {
+      nsTableRowGroupFrame* rgFrame = orderedRowGroups[rgIndex];
+      nsTableRowFrame* row = rgFrame->GetFirstRow();
+      if (row) {
+        return TableBaseline(rgFrame, row);
+      }
+    }
+  } else {
+    for (uint32_t rgIndex = orderedRowGroups.Length(); rgIndex-- > 0;) {
+      nsTableRowGroupFrame* rgFrame = orderedRowGroups[rgIndex];
+      nsTableRowFrame* row = rgFrame->GetLastRow();
+      if (row) {
+        return TableBaseline(rgFrame, row).map([this, aWM](nscoord aBaseline) {
+          return BSize(aWM) - aBaseline;
+        });
+      }
+    }
+  }
+  return Nothing{};
+}
+
+/* ----- global methods ----- */
+
+nsTableFrame* NS_NewTableFrame(PresShell* aPresShell, ComputedStyle* aStyle) {
+  return new (aPresShell) nsTableFrame(aStyle, aPresShell->GetPresContext());
+}
+
+NS_IMPL_FRAMEARENA_HELPERS(nsTableFrame)
+
+nsTableFrame* nsTableFrame::GetTableFrame(nsIFrame* aFrame) {
+  for (nsIFrame* ancestor = aFrame->GetParent(); ancestor;
+       ancestor = ancestor->GetParent()) {
+    if (ancestor->IsTableFrame()) {
+      return static_cast<nsTableFrame*>(ancestor);
+    }
+  }
+  MOZ_CRASH("unable to find table parent");
+  return nullptr;
+}
+
+bool nsTableFrame::IsAutoBSize(WritingMode aWM) {
+  const auto& bsize = StylePosition()->BSize(aWM);
+  if (bsize.IsAuto()) {
+    return true;
+  }
+  return bsize.ConvertsToPercentage() && bsize.ToPercentage() <= 0.0f;
+}
+
+nscoord nsTableFrame::CalcBorderBoxBSize(const ReflowInput& aReflowInput,
+                                         const LogicalMargin& aBorderPadding,
+                                         nscoord aIntrinsicBorderBoxBSize) {
+  WritingMode wm = aReflowInput.GetWritingMode();
+  nscoord bSize = aReflowInput.ComputedBSize();
+  nscoord bp = aBorderPadding.BStartEnd(wm);
+  if (bSize == NS_UNCONSTRAINEDSIZE) {
+    if (aIntrinsicBorderBoxBSize == NS_UNCONSTRAINEDSIZE) {
+      return NS_UNCONSTRAINEDSIZE;
+    }
+    bSize = std::max(0, aIntrinsicBorderBoxBSize - bp);
+  }
+  return aReflowInput.ApplyMinMaxBSize(bSize) + bp;
+}
+
+bool nsTableFrame::IsAutoLayout() {
+  if (StyleTable()->mLayoutStrategy == StyleTableLayout::Auto) return true;
+  // a fixed-layout inline-table must have a inline size
+  // and tables with inline size set to 'max-content' must be
+  // auto-layout (at least as long as
+  // FixedTableLayoutStrategy::GetPrefISize returns nscoord_MAX)
+  const auto& iSize = StylePosition()->ISize(GetWritingMode());
+  return iSize.IsAuto() || iSize.IsMaxContent();
+}
+
+#ifdef DEBUG_FRAME_DUMP
+nsresult nsTableFrame::GetFrameName(nsAString& aResult) const {
+  return MakeFrameName(u"Table"_ns, aResult);
+}
+#endif
+
+// Find the closet sibling before aPriorChildFrame (including aPriorChildFrame)
+// that is of type aChildType
+nsIFrame* nsTableFrame::GetFrameAtOrBefore(nsIFrame* aParentFrame,
+                                           nsIFrame* aPriorChildFrame,
+                                           LayoutFrameType aChildType) {
+  nsIFrame* result = nullptr;
+  if (!aPriorChildFrame) {
+    return result;
+  }
+  if (aChildType == aPriorChildFrame->Type()) {
+    return aPriorChildFrame;
+  }
+
+  // aPriorChildFrame is not of type aChildType, so we need start from
+  // the beginnng and find the closest one
+  nsIFrame* lastMatchingFrame = nullptr;
+  nsIFrame* childFrame = aParentFrame->PrincipalChildList().FirstChild();
+  while (childFrame && (childFrame != aPriorChildFrame)) {
+    if (aChildType == childFrame->Type()) {
+      lastMatchingFrame = childFrame;
+    }
+    childFrame = childFrame->GetNextSibling();
+  }
+  return lastMatchingFrame;
+}
+
+#ifdef DEBUG
+void nsTableFrame::DumpRowGroup(nsIFrame* aKidFrame) {
+  if (!aKidFrame) return;
+
+  for (nsIFrame* cFrame : aKidFrame->PrincipalChildList()) {
+    nsTableRowFrame* rowFrame = do_QueryFrame(cFrame);
+    if (rowFrame) {
+      printf("row(%d)=%p ", rowFrame->GetRowIndex(),
+             static_cast<void*>(rowFrame));
+      for (nsIFrame* childFrame : cFrame->PrincipalChildList()) {
+        nsTableCellFrame* cellFrame = do_QueryFrame(childFrame);
+        if (cellFrame) {
+          uint32_t colIndex = cellFrame->ColIndex();
+          printf("cell(%u)=%p ", colIndex, static_cast<void*>(childFrame));
+        }
+      }
+      printf("\n");
+    } else {
+      DumpRowGroup(rowFrame);
+    }
+  }
+}
+
+void nsTableFrame::Dump(bool aDumpRows, bool aDumpCols, bool aDumpCellMap) {
+  printf("***START TABLE DUMP*** \n");
+  // dump the columns widths array
+  printf("mColWidths=");
+  int32_t numCols = GetColCount();
+  int32_t colIdx;
+  nsTableFrame* fif = static_cast<nsTableFrame*>(FirstInFlow());
+  for (colIdx = 0; colIdx < numCols; colIdx++) {
+    printf("%d ", fif->GetColumnISizeFromFirstInFlow(colIdx));
+  }
+  printf("\n");
+
+  if (aDumpRows) {
+    nsIFrame* kidFrame = mFrames.FirstChild();
+    while (kidFrame) {
+      DumpRowGroup(kidFrame);
+      kidFrame = kidFrame->GetNextSibling();
+    }
+  }
+
+  if (aDumpCols) {
+    // output col frame cache
+    printf("\n col frame cache ->");
+    for (colIdx = 0; colIdx < numCols; colIdx++) {
+      nsTableColFrame* colFrame = mColFrames.ElementAt(colIdx);
+      if (0 == (colIdx % 8)) {
+        printf("\n");
+      }
+      printf("%d=%p ", colIdx, static_cast<void*>(colFrame));
+      nsTableColType colType = colFrame->GetColType();
+      switch (colType) {
+        case eColContent:
+          printf(" content ");
+          break;
+        case eColAnonymousCol:
+          printf(" anonymous-column ");
+          break;
+        case eColAnonymousColGroup:
+          printf(" anonymous-colgroup ");
+          break;
+        case eColAnonymousCell:
+          printf(" anonymous-cell ");
+          break;
+      }
+    }
+    printf("\n colgroups->");
+    for (nsIFrame* childFrame : mColGroups) {
+      if (LayoutFrameType::TableColGroup == childFrame->Type()) {
+        nsTableColGroupFrame* colGroupFrame = (nsTableColGroupFrame*)childFrame;
+        colGroupFrame->Dump(1);
+      }
+    }
+    for (colIdx = 0; colIdx < numCols; colIdx++) {
+      printf("\n");
+      nsTableColFrame* colFrame = GetColFrame(colIdx);
+      colFrame->Dump(1);
+    }
+  }
+  if (aDumpCellMap) {
+    nsTableCellMap* cellMap = GetCellMap();
+    cellMap->Dump();
+  }
+  printf(" ***END TABLE DUMP*** \n");
+}
+#endif
+
+bool nsTableFrame::ColumnHasCellSpacingBefore(int32_t aColIndex) const {
+  if (aColIndex == 0) {
+    return true;
+  }
+  // Since fixed-layout tables should not have their column sizes change
+  // as they load, we assume that all columns are significant.
+  auto* fif = static_cast<nsTableFrame*>(FirstInFlow());
+  if (fif->LayoutStrategy()->GetType() == nsITableLayoutStrategy::Fixed) {
+    return true;
+  }
+  nsTableCellMap* cellMap = fif->GetCellMap();
+  if (!cellMap) {
+    return false;
+  }
+  if (cellMap->GetNumCellsOriginatingInCol(aColIndex) > 0) {
+    return true;
+  }
+  // Check if we have a <col> element with a non-zero definite inline size.
+  // Note: percentages and calc(%) are intentionally not considered.
+  if (const auto* col = fif->GetColFrame(aColIndex)) {
+    const auto& iSize = col->StylePosition()->ISize(GetWritingMode());
+    if (iSize.ConvertsToLength() && iSize.ToLength() > 0) {
+      const auto& maxISize = col->StylePosition()->MaxISize(GetWritingMode());
+      if (!maxISize.ConvertsToLength() || maxISize.ToLength() > 0) {
+        return true;
+      }
+    }
+    const auto& minISize = col->StylePosition()->MinISize(GetWritingMode());
+    if (minISize.ConvertsToLength() && minISize.ToLength() > 0) {
+      return true;
+    }
+  }
+  return false;
+}
+
+/********************************************************************************
+ * Collapsing Borders
+ *
+ *  The CSS spec says to resolve border conflicts in this order:
+ *  1) any border with the style HIDDEN wins
+ *  2) the widest border with a style that is not NONE wins
+ *  3) the border styles are ranked in this order, highest to lowest precedence:
+ *     double, solid, dashed, dotted, ridge, outset, groove, inset
+ *  4) borders that are of equal width and style (differ only in color) have
+ *     this precedence: cell, row, rowgroup, col, colgroup, table
+ *  5) if all border styles are NONE, then that's the computed border style.
+ *******************************************************************************/
+
+#ifdef DEBUG
+#  define VerifyNonNegativeDamageRect(r)                       \
+    NS_ASSERTION((r).StartCol() >= 0, "negative col index");   \
+    NS_ASSERTION((r).StartRow() >= 0, "negative row index");   \
+    NS_ASSERTION((r).ColCount() >= 0, "negative cols damage"); \
+    NS_ASSERTION((r).RowCount() >= 0, "negative rows damage");
+#  define VerifyDamageRect(r)                          \
+    VerifyNonNegativeDamageRect(r);                    \
+    NS_ASSERTION((r).EndCol() <= GetColCount(),        \
+                 "cols damage extends outside table"); \
+    NS_ASSERTION((r).EndRow() <= GetRowCount(),        \
+                 "rows damage extends outside table");
+#endif
+
+void nsTableFrame::AddBCDamageArea(const TableArea& aValue) {
+  MOZ_ASSERT(IsBorderCollapse(),
+             "Why call this if we are not border-collapsed?");
+#ifdef DEBUG
+  VerifyDamageRect(aValue);
+#endif
+
+  SetNeedToCalcBCBorders(true);
+  SetNeedToCalcHasBCBorders(true);
+  // Get the property
+  TableBCData* value = GetOrCreateTableBCData();
+
+#ifdef DEBUG
+  VerifyNonNegativeDamageRect(value->mDamageArea);
+#endif
+  // Clamp the old damage area to the current table area in case it shrunk.
+  int32_t cols = GetColCount();
+  if (value->mDamageArea.EndCol() > cols) {
+    if (value->mDamageArea.StartCol() > cols) {
+      value->mDamageArea.StartCol() = cols;
+      value->mDamageArea.ColCount() = 0;
+    } else {
+      value->mDamageArea.ColCount() = cols - value->mDamageArea.StartCol();
+    }
+  }
+  int32_t rows = GetRowCount();
+  if (value->mDamageArea.EndRow() > rows) {
+    if (value->mDamageArea.StartRow() > rows) {
+      value->mDamageArea.StartRow() = rows;
+      value->mDamageArea.RowCount() = 0;
+    } else {
+      value->mDamageArea.RowCount() = rows - value->mDamageArea.StartRow();
+    }
+  }
+
+  // Construct a union of the new and old damage areas.
+  value->mDamageArea.UnionArea(value->mDamageArea, aValue);
+}
+
+void nsTableFrame::SetFullBCDamageArea() {
+  MOZ_ASSERT(IsBorderCollapse(),
+             "Why call this if we are not border-collapsed?");
+
+  SetNeedToCalcBCBorders(true);
+  SetNeedToCalcHasBCBorders(true);
+
+  TableBCData* value = GetOrCreateTableBCData();
+  value->mDamageArea = TableArea(0, 0, GetColCount(), GetRowCount());
+}
+
+/* BCCellBorder represents a border segment which can be either an inline-dir
+ * or a block-dir segment. For each segment we need to know the color, width,
+ * style, who owns it and how long it is in cellmap coordinates.
+ * Ownership of these segments is important to calculate which corners should
+ * be bevelled. This structure has dual use, its used first to compute the
+ * dominant border for inline-dir and block-dir segments and to store the
+ * preliminary computed border results in the BCCellBorders structure.
+ * This temporary storage is not symmetric with respect to inline-dir and
+ * block-dir border segments, its always column oriented. For each column in
+ * the cellmap there is a temporary stored block-dir and inline-dir segment.
+ * XXX_Bernd this asymmetry is the root of those rowspan bc border errors
+ */
+struct BCCellBorder {
+  BCCellBorder() { Reset(0, 1); }
+  void Reset(uint32_t aRowIndex, uint32_t aRowSpan);
+  nscolor color;           // border segment color
+  BCPixelSize width;       // border segment width in pixel coordinates !!
+  StyleBorderStyle style;  // border segment style, possible values are defined
+                           // in nsStyleConsts.h as StyleBorderStyle::*
+  BCBorderOwner owner;     // border segment owner, possible values are defined
+                           // in celldata.h. In the cellmap for each border
+                           // segment we store the owner and later when
+                           // painting we know the owner and can retrieve the
+                           // style info from the corresponding frame
+  int32_t rowIndex;        // rowIndex of temporary stored inline-dir border
+                           // segments relative to the table
+  int32_t rowSpan;         // row span of temporary stored inline-dir border
+                           // segments
+};
+
+void BCCellBorder::Reset(uint32_t aRowIndex, uint32_t aRowSpan) {
+  style = StyleBorderStyle::None;
+  color = 0;
+  width = 0;
+  owner = eTableOwner;
+  rowIndex = aRowIndex;
+  rowSpan = aRowSpan;
+}
+
+class BCMapCellIterator;
+
+/*****************************************************************
+ *  BCMapCellInfo
+ * This structure stores information about the cellmap and all involved
+ * table related frames that are used during the computation of winning borders
+ * in CalcBCBorders so that they do need to be looked up again and again when
+ * iterating over the cells.
+ ****************************************************************/
+struct BCMapCellInfo {
+  explicit BCMapCellInfo(nsTableFrame* aTableFrame);
+  void ResetCellInfo();
+  void SetInfo(nsTableRowFrame* aNewRow, int32_t aColIndex,
+               BCCellData* aCellData, BCMapCellIterator* aIter,
+               nsCellMap* aCellMap = nullptr);
+
+  // functions to set the border widths on the table related frames, where the
+  // knowledge about the current position in the table is used.
+  void SetTableBStartBorderWidth(BCPixelSize aWidth);
+  void SetTableIStartBorderWidth(int32_t aRowB, BCPixelSize aWidth);
+  void SetTableIEndBorderWidth(int32_t aRowB, BCPixelSize aWidth);
+  void SetTableBEndBorderWidth(BCPixelSize aWidth);
+  void SetIStartBorderWidths(BCPixelSize aWidth);
+  void SetIEndBorderWidths(BCPixelSize aWidth);
+  void SetBStartBorderWidths(BCPixelSize aWidth);
+  void SetBEndBorderWidths(BCPixelSize aWidth);
+
+  // functions to compute the borders; they depend on the
+  // knowledge about the current position in the table. The edge functions
+  // should be called if a table edge is involved, otherwise the internal
+  // functions should be called.
+  BCCellBorder GetBStartEdgeBorder();
+  BCCellBorder GetBEndEdgeBorder();
+  BCCellBorder GetIStartEdgeBorder();
+  BCCellBorder GetIEndEdgeBorder();
+  BCCellBorder GetIEndInternalBorder();
+  BCCellBorder GetIStartInternalBorder();
+  BCCellBorder GetBStartInternalBorder();
+  BCCellBorder GetBEndInternalBorder();
+
+  // functions to set the internal position information
+  void SetColumn(int32_t aColX);
+  // Increment the row as we loop over the rows of a rowspan
+  void IncrementRow(bool aResetToBStartRowOfCell = false);
+
+  // Helper functions to get extent of the cell
+  int32_t GetCellEndRowIndex() const;
+  int32_t GetCellEndColIndex() const;
+
+  // storage of table information
+  nsTableFrame* mTableFrame;
+  nsTableFrame* mTableFirstInFlow;
+  int32_t mNumTableRows;
+  int32_t mNumTableCols;
+  TableBCData* mTableBCData;
+  WritingMode mTableWM;
+
+  // a cell can only belong to one rowgroup
+  nsTableRowGroupFrame* mRowGroup;
+
+  // a cell with a rowspan has a bstart and a bend row, and rows in between
+  nsTableRowFrame* mStartRow;
+  nsTableRowFrame* mEndRow;
+  nsTableRowFrame* mCurrentRowFrame;
+
+  // a cell with a colspan has an istart and iend column and columns in between
+  // they can belong to different colgroups
+  nsTableColGroupFrame* mColGroup;
+  nsTableColGroupFrame* mCurrentColGroupFrame;
+
+  nsTableColFrame* mStartCol;
+  nsTableColFrame* mEndCol;
+  nsTableColFrame* mCurrentColFrame;
+
+  // cell information
+  BCCellData* mCellData;
+  nsBCTableCellFrame* mCell;
+
+  int32_t mRowIndex;
+  int32_t mRowSpan;
+  int32_t mColIndex;
+  int32_t mColSpan;
+
+  // flags to describe the position of the cell with respect to the row- and
+  // colgroups, for instance mRgAtStart documents that the bStart cell border
+  // hits a rowgroup border
+  bool mRgAtStart;
+  bool mRgAtEnd;
+  bool mCgAtStart;
+  bool mCgAtEnd;
+};
+
+BCMapCellInfo::BCMapCellInfo(nsTableFrame* aTableFrame)
+    : mTableFrame(aTableFrame),
+      mTableFirstInFlow(static_cast<nsTableFrame*>(aTableFrame->FirstInFlow())),
+      mNumTableRows(aTableFrame->GetRowCount()),
+      mNumTableCols(aTableFrame->GetColCount()),
+      mTableBCData(mTableFirstInFlow->GetTableBCData()),
+      mTableWM(aTableFrame->Style()),
+      mCurrentRowFrame(nullptr),
+      mCurrentColGroupFrame(nullptr),
+      mCurrentColFrame(nullptr) {
+  ResetCellInfo();
+}
+
+void BCMapCellInfo::ResetCellInfo() {
+  mCellData = nullptr;
+  mRowGroup = nullptr;
+  mStartRow = nullptr;
+  mEndRow = nullptr;
+  mColGroup = nullptr;
+  mStartCol = nullptr;
+  mEndCol = nullptr;
+  mCell = nullptr;
+  mRowIndex = mRowSpan = mColIndex = mColSpan = 0;
+  mRgAtStart = mRgAtEnd = mCgAtStart = mCgAtEnd = false;
+}
+
+inline int32_t BCMapCellInfo::GetCellEndRowIndex() const {
+  return mRowIndex + mRowSpan - 1;
+}
+
+inline int32_t BCMapCellInfo::GetCellEndColIndex() const {
+  return mColIndex + mColSpan - 1;
+}
+
+class BCMapCellIterator {
+ public:
+  BCMapCellIterator(nsTableFrame* aTableFrame, const TableArea& aDamageArea);
+
+  void First(BCMapCellInfo& aMapCellInfo);
+
+  void Next(BCMapCellInfo& aMapCellInfo);
+
+  void PeekIEnd(BCMapCellInfo& aRefInfo, uint32_t aRowIndex,
+                BCMapCellInfo& aAjaInfo);
+
+  void PeekBEnd(BCMapCellInfo& aRefInfo, uint32_t aColIndex,
+                BCMapCellInfo& aAjaInfo);
+
+  bool IsNewRow() { return mIsNewRow; }
+
+  nsTableRowFrame* GetPrevRow() const { return mPrevRow; }
+  nsTableRowFrame* GetCurrentRow() const { return mRow; }
+  nsTableRowGroupFrame* GetCurrentRowGroup() const { return mRowGroup; }
+
+  int32_t mRowGroupStart;
+  int32_t mRowGroupEnd;
+  bool mAtEnd;
+  nsCellMap* mCellMap;
+
+ private:
+  bool SetNewRow(nsTableRowFrame* row = nullptr);
+  bool SetNewRowGroup(bool aFindFirstDamagedRow);
+
+  nsTableFrame* mTableFrame;
+  nsTableCellMap* mTableCellMap;
+  nsTableFrame::RowGroupArray mRowGroups;
+  nsTableRowGroupFrame* mRowGroup;
+  int32_t mRowGroupIndex;
+  uint32_t mNumTableRows;
+  nsTableRowFrame* mRow;
+  nsTableRowFrame* mPrevRow;
+  bool mIsNewRow;
+  int32_t mRowIndex;
+  uint32_t mNumTableCols;
+  int32_t mColIndex;
+  // We don't necessarily want to traverse all areas
+  // of the table - mArea(Start|End) specify the area to traverse.
+  // TODO(dshin): Should be not abuse `nsPoint` for this - See bug 1879847.
+  nsPoint mAreaStart;
+  nsPoint mAreaEnd;
+};
+
+BCMapCellIterator::BCMapCellIterator(nsTableFrame* aTableFrame,
+                                     const TableArea& aDamageArea)
+    : mRowGroupStart(0),
+      mRowGroupEnd(0),
+      mCellMap(nullptr),
+      mTableFrame(aTableFrame),
+      mRowGroups(aTableFrame->OrderedRowGroups()),
+      mRowGroup(nullptr),
+      mPrevRow(nullptr),
+      mIsNewRow(false) {
+  mTableCellMap = aTableFrame->GetCellMap();
+
+  mAreaStart.x = aDamageArea.StartCol();
+  mAreaStart.y = aDamageArea.StartRow();
+  mAreaEnd.x = aDamageArea.EndCol() - 1;
+  mAreaEnd.y = aDamageArea.EndRow() - 1;
+
+  mNumTableRows = mTableFrame->GetRowCount();
+  mRow = nullptr;
+  mRowIndex = 0;
+  mNumTableCols = mTableFrame->GetColCount();
+  mColIndex = 0;
+  mRowGroupIndex = -1;
+
+  mAtEnd = true;  // gets reset when First() is called
+}
+
+// fill fields that we need for border collapse computation on a given cell
+void BCMapCellInfo::SetInfo(nsTableRowFrame* aNewRow, int32_t aColIndex,
+                            BCCellData* aCellData, BCMapCellIterator* aIter,
+                            nsCellMap* aCellMap) {
+  // fill the cell information
+  mCellData = aCellData;
+  mColIndex = aColIndex;
+
+  // initialize the row information if it was not previously set for cells in
+  // this row
+  mRowIndex = 0;
+  if (aNewRow) {
+    mStartRow = aNewRow;
+    mRowIndex = aNewRow->GetRowIndex();
+  }
+
+  // fill cell frame info and row information
+  mCell = nullptr;
+  mRowSpan = 1;
+  mColSpan = 1;
+  if (aCellData) {
+    mCell = static_cast<nsBCTableCellFrame*>(aCellData->GetCellFrame());
+    if (mCell) {
+      if (!mStartRow) {
+        mStartRow = mCell->GetTableRowFrame();
+        if (!mStartRow) ABORT0();
+        mRowIndex = mStartRow->GetRowIndex();
+      }
+      mColSpan = mTableFrame->GetEffectiveColSpan(*mCell, aCellMap);
+      mRowSpan = mTableFrame->GetEffectiveRowSpan(*mCell, aCellMap);
+    }
+  }
+
+  if (!mStartRow) {
+    mStartRow = aIter->GetCurrentRow();
+  }
+  if (1 == mRowSpan) {
+    mEndRow = mStartRow;
+  } else {
+    mEndRow = mStartRow->GetNextRow();
+    if (mEndRow) {
+      for (int32_t span = 2; mEndRow && span < mRowSpan; span++) {
+        mEndRow = mEndRow->GetNextRow();
+      }
+      NS_ASSERTION(mEndRow, "spanned row not found");
+    } else {
+      NS_ERROR("error in cell map");
+      mRowSpan = 1;
+      mEndRow = mStartRow;
+    }
+  }
+  // row group frame info
+  // try to reuse the rgStart and rgEnd from the iterator as calls to
+  // GetRowCount() are computationally expensive and should be avoided if
+  // possible
+  uint32_t rgStart = aIter->mRowGroupStart;
+  uint32_t rgEnd = aIter->mRowGroupEnd;
+  mRowGroup = mStartRow->GetTableRowGroupFrame();
+  if (mRowGroup != aIter->GetCurrentRowGroup()) {
+    rgStart = mRowGroup->GetStartRowIndex();
+    rgEnd = rgStart + mRowGroup->GetRowCount() - 1;
+  }
+  uint32_t rowIndex = mStartRow->GetRowIndex();
+  mRgAtStart = rgStart == rowIndex;
+  mRgAtEnd = rgEnd == rowIndex + mRowSpan - 1;
+
+  // col frame info
+  mStartCol = mTableFirstInFlow->GetColFrame(aColIndex);
+  if (!mStartCol) ABORT0();
+
+  mEndCol = mStartCol;
+  if (mColSpan > 1) {
+    nsTableColFrame* colFrame =
+        mTableFirstInFlow->GetColFrame(aColIndex + mColSpan - 1);
+    if (!colFrame) ABORT0();
+    mEndCol = colFrame;
+  }
+
+  // col group frame info
+  mColGroup = mStartCol->GetTableColGroupFrame();
+  int32_t cgStart = mColGroup->GetStartColumnIndex();
+  int32_t cgEnd = std::max(0, cgStart + mColGroup->GetColCount() - 1);
+  mCgAtStart = cgStart == aColIndex;
+  mCgAtEnd = cgEnd == aColIndex + mColSpan - 1;
+}
+
+bool BCMapCellIterator::SetNewRow(nsTableRowFrame* aRow) {
+  mAtEnd = true;
+  mPrevRow = mRow;
+  if (aRow) {
+    mRow = aRow;
+  } else if (mRow) {
+    mRow = mRow->GetNextRow();
+  }
+  if (mRow) {
+    mRowIndex = mRow->GetRowIndex();
+    // get to the first entry with an originating cell
+    int32_t rgRowIndex = mRowIndex - mRowGroupStart;
+    if (uint32_t(rgRowIndex) >= mCellMap->mRows.Length()) ABORT1(false);
+    const nsCellMap::CellDataArray& row = mCellMap->mRows[rgRowIndex];
+
+    for (mColIndex = mAreaStart.x; mColIndex <= mAreaEnd.x; mColIndex++) {
+      CellData* cellData = row.SafeElementAt(mColIndex);
+      if (!cellData) {  // add a dead cell data
+        TableArea damageArea;
+        cellData = mCellMap->AppendCell(*mTableCellMap, nullptr, rgRowIndex,
+                                        false, 0, damageArea);
+        if (!cellData) ABORT1(false);
+      }
+      if (cellData && (cellData->IsOrig() || cellData->IsDead())) {
+        break;
+      }
+    }
+    mIsNewRow = true;
+    mAtEnd = false;
+  } else
+    ABORT1(false);
+
+  return !mAtEnd;
+}
+
+bool BCMapCellIterator::SetNewRowGroup(bool aFindFirstDamagedRow) {
+  mAtEnd = true;
+  int32_t numRowGroups = mRowGroups.Length();
+  mCellMap = nullptr;
+  for (mRowGroupIndex++; mRowGroupIndex < numRowGroups; mRowGroupIndex++) {
+    mRowGroup = mRowGroups[mRowGroupIndex];
+    int32_t rowCount = mRowGroup->GetRowCount();
+    mRowGroupStart = mRowGroup->GetStartRowIndex();
+    mRowGroupEnd = mRowGroupStart + rowCount - 1;
+    if (rowCount > 0) {
+      mCellMap = mTableCellMap->GetMapFor(mRowGroup, mCellMap);
+      if (!mCellMap) ABORT1(false);
+      nsTableRowFrame* firstRow = mRowGroup->GetFirstRow();
+      if (aFindFirstDamagedRow) {
+        if ((mAreaStart.y >= mRowGroupStart) &&
+            (mAreaStart.y <= mRowGroupEnd)) {
+          // the damage area starts in the row group
+
+          // find the correct first damaged row
+          int32_t numRows = mAreaStart.y - mRowGroupStart;
+          for (int32_t i = 0; i < numRows; i++) {
+            firstRow = firstRow->GetNextRow();
+            if (!firstRow) ABORT1(false);
+          }
+
+        } else {
+          continue;
+        }
+      }
+      if (SetNewRow(firstRow)) {  // sets mAtEnd
+        break;
+      }
+    }
+  }
+
+  return !mAtEnd;
+}
+
+void BCMapCellIterator::First(BCMapCellInfo& aMapInfo) {
+  aMapInfo.ResetCellInfo();
+
+  SetNewRowGroup(true);  // sets mAtEnd
+  while (!mAtEnd) {
+    if ((mAreaStart.y >= mRowGroupStart) && (mAreaStart.y <= mRowGroupEnd)) {
+      BCCellData* cellData = static_cast<BCCellData*>(
+          mCellMap->GetDataAt(mAreaStart.y - mRowGroupStart, mAreaStart.x));
+      if (cellData && (cellData->IsOrig() || cellData->IsDead())) {
+        aMapInfo.SetInfo(mRow, mAreaStart.x, cellData, this);
+        return;
+      } else {
+        NS_ASSERTION(((0 == mAreaStart.x) && (mRowGroupStart == mAreaStart.y)),
+                     "damage area expanded incorrectly");
+      }
+    }
+    SetNewRowGroup(true);  // sets mAtEnd
+  }
+}
+
+void BCMapCellIterator::Next(BCMapCellInfo& aMapInfo) {
+  if (mAtEnd) ABORT0();
+  aMapInfo.ResetCellInfo();
+
+  mIsNewRow = false;
+  mColIndex++;
+  while ((mRowIndex <= mAreaEnd.y) && !mAtEnd) {
+    for (; mColIndex <= mAreaEnd.x; mColIndex++) {
+      int32_t rgRowIndex = mRowIndex - mRowGroupStart;
+      BCCellData* cellData =
+          static_cast<BCCellData*>(mCellMap->GetDataAt(rgRowIndex, mColIndex));
+      if (!cellData) {  // add a dead cell data
+        TableArea damageArea;
+        cellData = static_cast<BCCellData*>(mCellMap->AppendCell(
+            *mTableCellMap, nullptr, rgRowIndex, false, 0, damageArea));
+        if (!cellData) ABORT0();
+      }
+      if (cellData && (cellData->IsOrig() || cellData->IsDead())) {
+        aMapInfo.SetInfo(mRow, mColIndex, cellData, this);
+        return;
+      }
+    }
+    if (mRowIndex >= mRowGroupEnd) {
+      SetNewRowGroup(false);  // could set mAtEnd
+    } else {
+      SetNewRow();  // could set mAtEnd
+    }
+  }
+  mAtEnd = true;
+}
+
+void BCMapCellIterator::PeekIEnd(BCMapCellInfo& aRefInfo, uint32_t aRowIndex,
+                                 BCMapCellInfo& aAjaInfo) {
+  aAjaInfo.ResetCellInfo();
+  int32_t colIndex = aRefInfo.mColIndex + aRefInfo.mColSpan;
+  uint32_t rgRowIndex = aRowIndex - mRowGroupStart;
+
+  BCCellData* cellData =
+      static_cast<BCCellData*>(mCellMap->GetDataAt(rgRowIndex, colIndex));
+  if (!cellData) {  // add a dead cell data
+    NS_ASSERTION(colIndex < mTableCellMap->GetColCount(), "program error");
+    TableArea damageArea;
+    cellData = static_cast<BCCellData*>(mCellMap->AppendCell(
+        *mTableCellMap, nullptr, rgRowIndex, false, 0, damageArea));
+    if (!cellData) ABORT0();
+  }
+  nsTableRowFrame* row = nullptr;
+  if (cellData->IsRowSpan()) {
+    rgRowIndex -= cellData->GetRowSpanOffset();
+    cellData =
+        static_cast<BCCellData*>(mCellMap->GetDataAt(rgRowIndex, colIndex));
+    if (!cellData) ABORT0();
+  } else {
+    row = mRow;
+  }
+  aAjaInfo.SetInfo(row, colIndex, cellData, this);
+}
+
+void BCMapCellIterator::PeekBEnd(BCMapCellInfo& aRefInfo, uint32_t aColIndex,
+                                 BCMapCellInfo& aAjaInfo) {
+  aAjaInfo.ResetCellInfo();
+  int32_t rowIndex = aRefInfo.mRowIndex + aRefInfo.mRowSpan;
+  int32_t rgRowIndex = rowIndex - mRowGroupStart;
+  nsTableRowGroupFrame* rg = mRowGroup;
+  nsCellMap* cellMap = mCellMap;
+  nsTableRowFrame* nextRow = nullptr;
+  if (rowIndex > mRowGroupEnd) {
+    int32_t nextRgIndex = mRowGroupIndex;
+    do {
+      nextRgIndex++;
+      rg = mRowGroups.SafeElementAt(nextRgIndex);
+      if (rg) {
+        cellMap = mTableCellMap->GetMapFor(rg, cellMap);
+        if (!cellMap) ABORT0();
+        rgRowIndex = 0;
+        nextRow = rg->GetFirstRow();
+      }
+    } while (rg && !nextRow);
+    if (!rg) return;
+  } else {
+    // get the row within the same row group
+    nextRow = mRow;
+    for (int32_t i = 0; i < aRefInfo.mRowSpan; i++) {
+      nextRow = nextRow->GetNextRow();
+      if (!nextRow) ABORT0();
+    }
+  }
+
+  BCCellData* cellData =
+      static_cast<BCCellData*>(cellMap->GetDataAt(rgRowIndex, aColIndex));
+  if (!cellData) {  // add a dead cell data
+    NS_ASSERTION(rgRowIndex < cellMap->GetRowCount(), "program error");
+    TableArea damageArea;
+    cellData = static_cast<BCCellData*>(cellMap->AppendCell(
+        *mTableCellMap, nullptr, rgRowIndex, false, 0, damageArea));
+    if (!cellData) ABORT0();
+  }
+  if (cellData->IsColSpan()) {
+    aColIndex -= cellData->GetColSpanOffset();
+    cellData =
+        static_cast<BCCellData*>(cellMap->GetDataAt(rgRowIndex, aColIndex));
+  }
+  aAjaInfo.SetInfo(nextRow, aColIndex, cellData, this, cellMap);
+}
+
+#define CELL_CORNER true
+
+/** return the border style, border color and optionally the width in
+ * pixel for a given frame and side
+ * @param aFrame           - query the info for this frame
+ * @param aTableWM         - the writing-mode of the frame
+ * @param aSide            - the side of the frame
+ * @param aStyle           - the border style
+ * @param aColor           - the border color
+ * @param aWidth           - the border width in px
+ */
+static void GetColorAndStyle(const nsIFrame* aFrame, WritingMode aTableWM,
+                             LogicalSide aSide, StyleBorderStyle* aStyle,
+                             nscolor* aColor, BCPixelSize* aWidth = nullptr) {
+  MOZ_ASSERT(aFrame, "null frame");
+  MOZ_ASSERT(aStyle && aColor, "null argument");
+
+  // initialize out arg
+  *aColor = 0;
+  if (aWidth) {
+    *aWidth = 0;
+  }
+
+  const nsStyleBorder* styleData = aFrame->StyleBorder();
+  mozilla::Side physicalSide = aTableWM.PhysicalSide(aSide);
+  *aStyle = styleData->GetBorderStyle(physicalSide);
+
+  if ((StyleBorderStyle::None == *aStyle) ||
+      (StyleBorderStyle::Hidden == *aStyle)) {
+    return;
+  }
+  *aColor = aFrame->Style()->GetVisitedDependentColor(
+      nsStyleBorder::BorderColorFieldFor(physicalSide));
+
+  if (aWidth) {
+    nscoord width = styleData->GetComputedBorderWidth(physicalSide);
+    *aWidth = aFrame->PresContext()->AppUnitsToDevPixels(width);
+  }
+}
+
+/** coerce the paint style as required by CSS2.1
+ * @param aFrame           - query the info for this frame
+ * @param aTableWM         - the writing mode of the frame
+ * @param aSide            - the side of the frame
+ * @param aStyle           - the border style
+ * @param aColor           - the border color
+ */
+static void GetPaintStyleInfo(const nsIFrame* aFrame, WritingMode aTableWM,
+                              LogicalSide aSide, StyleBorderStyle* aStyle,
+                              nscolor* aColor) {
+  GetColorAndStyle(aFrame, aTableWM, aSide, aStyle, aColor);
+  if (StyleBorderStyle::Inset == *aStyle) {
+    *aStyle = StyleBorderStyle::Ridge;
+  } else if (StyleBorderStyle::Outset == *aStyle) {
+    *aStyle = StyleBorderStyle::Groove;
+  }
+}
+
+class nsDelayedCalcBCBorders : public Runnable {
+ public:
+  explicit nsDelayedCalcBCBorders(nsIFrame* aFrame)
+      : mozilla::Runnable("nsDelayedCalcBCBorders"), mFrame(aFrame) {}
+
+  NS_IMETHOD Run() override {
+    if (mFrame) {
+      nsTableFrame* tableFrame = static_cast<nsTableFrame*>(mFrame.GetFrame());
+      if (tableFrame->NeedToCalcBCBorders()) {
+        tableFrame->CalcBCBorders();
+      }
+    }
+    return NS_OK;
+  }
+
+ private:
+  WeakFrame mFrame;
+};
+
+bool nsTableFrame::BCRecalcNeeded(ComputedStyle* aOldComputedStyle,
+                                  ComputedStyle* aNewComputedStyle) {
+  // Attention: the old ComputedStyle is the one we're forgetting,
+  // and hence possibly completely bogus for GetStyle* purposes.
+  // We use PeekStyleData instead.
+
+  const nsStyleBorder* oldStyleData = aOldComputedStyle->StyleBorder();
+  const nsStyleBorder* newStyleData = aNewComputedStyle->StyleBorder();
+  nsChangeHint change = newStyleData->CalcDifference(*oldStyleData);
+  if (!change) return false;
+  if (change & nsChangeHint_NeedReflow)
+    return true;  // the caller only needs to mark the bc damage area
+  if (change & nsChangeHint_RepaintFrame) {
+    // we need to recompute the borders and the caller needs to mark
+    // the bc damage area
+    // XXX In principle this should only be necessary for border style changes
+    // However the bc painting code tries to maximize the drawn border segments
+    // so it stores in the cellmap where a new border segment starts and this
+    // introduces a unwanted cellmap data dependence on color
+    nsCOMPtr<nsIRunnable> evt = new nsDelayedCalcBCBorders(this);
+    nsresult rv = GetContent()->OwnerDoc()->Dispatch(evt.forget());
+    return NS_SUCCEEDED(rv);
+  }
+  return false;
+}
+
+// Compare two border segments, this comparison depends whether the two
+// segments meet at a corner and whether the second segment is inline-dir.
+// The return value is whichever of aBorder1 or aBorder2 dominates.
+static const BCCellBorder& CompareBorders(
+    bool aIsCorner,  // Pass true for corner calculations
+    const BCCellBorder& aBorder1, const BCCellBorder& aBorder2,
+    bool aSecondIsInlineDir, bool* aFirstDominates = nullptr) {
+  bool firstDominates = true;
+
+  if (StyleBorderStyle::Hidden == aBorder1.style) {
+    firstDominates = !aIsCorner;
+  } else if (StyleBorderStyle::Hidden == aBorder2.style) {
+    firstDominates = aIsCorner;
+  } else if (aBorder1.width < aBorder2.width) {
+    firstDominates = false;
+  } else if (aBorder1.width == aBorder2.width) {
+    if (static_cast<uint8_t>(aBorder1.style) <
+        static_cast<uint8_t>(aBorder2.style)) {
+      firstDominates = false;
+    } else if (aBorder1.style == aBorder2.style) {
+      if (aBorder1.owner == aBorder2.owner) {
+        firstDominates = !aSecondIsInlineDir;
+      } else if (aBorder1.owner < aBorder2.owner) {
+        firstDominates = false;
+      }
+    }
+  }
+
+  if (aFirstDominates) *aFirstDominates = firstDominates;
+
+  if (firstDominates) return aBorder1;
+  return aBorder2;
+}
+
+/** calc the dominant border by considering the table, row/col group, row/col,
+ * cell.
+ * Depending on whether the side is block-dir or inline-dir and whether
+ * adjacent frames are taken into account the ownership of a single border
+ * segment is defined. The return value is the dominating border
+ * The cellmap stores only bstart and istart borders for each cellmap position.
+ * If the cell border is owned by the cell that is istart-wards of the border
+ * it will be an adjacent owner aka eAjaCellOwner. See celldata.h for the other
+ * scenarios with a adjacent owner.
+ * @param xxxFrame         - the frame for style information, might be zero if
+ *                           it should not be considered
+ * @param aTableWM         - the writing mode of the frame
+ * @param aSide            - side of the frames that should be considered
+ * @param aAja             - the border comparison takes place from the point of
+ *                           a frame that is adjacent to the cellmap entry, for
+ *                           when a cell owns its lower border it will be the
+ *                           adjacent owner as in the cellmap only bstart and
+ *                           istart borders are stored.
+ */
+static BCCellBorder CompareBorders(
+    const nsIFrame* aTableFrame, const nsIFrame* aColGroupFrame,
+    const nsIFrame* aColFrame, const nsIFrame* aRowGroupFrame,
+    const nsIFrame* aRowFrame, const nsIFrame* aCellFrame, WritingMode aTableWM,
+    LogicalSide aSide, bool aAja) {
+  BCCellBorder border, tempBorder;
+  bool inlineAxis = IsBlock(aSide);
+
+  // start with the table as dominant if present
+  if (aTableFrame) {
+    GetColorAndStyle(aTableFrame, aTableWM, aSide, &border.style, &border.color,
+                     &border.width);
+    border.owner = eTableOwner;
+    if (StyleBorderStyle::Hidden == border.style) {
+      return border;
+    }
+  }
+  // see if the colgroup is dominant
+  if (aColGroupFrame) {
+    GetColorAndStyle(aColGroupFrame, aTableWM, aSide, &tempBorder.style,
+                     &tempBorder.color, &tempBorder.width);
+    tempBorder.owner = aAja && !inlineAxis ? eAjaColGroupOwner : eColGroupOwner;
+    // pass here and below false for aSecondIsInlineDir as it is only used for
+    // corner calculations.
+    border = CompareBorders(!CELL_CORNER, border, tempBorder, false);
+    if (StyleBorderStyle::Hidden == border.style) {
+      return border;
+    }
+  }
+  // see if the col is dominant
+  if (aColFrame) {
+    GetColorAndStyle(aColFrame, aTableWM, aSide, &tempBorder.style,
+                     &tempBorder.color, &tempBorder.width);
+    tempBorder.owner = aAja && !inlineAxis ? eAjaColOwner : eColOwner;
+    border = CompareBorders(!CELL_CORNER, border, tempBorder, false);
+    if (StyleBorderStyle::Hidden == border.style) {
+      return border;
+    }
+  }
+  // see if the rowgroup is dominant
+  if (aRowGroupFrame) {
+    GetColorAndStyle(aRowGroupFrame, aTableWM, aSide, &tempBorder.style,
+                     &tempBorder.color, &tempBorder.width);
+    tempBorder.owner = aAja && inlineAxis ? eAjaRowGroupOwner : eRowGroupOwner;
+    border = CompareBorders(!CELL_CORNER, border, tempBorder, false);
+    if (StyleBorderStyle::Hidden == border.style) {
+      return border;
+    }
+  }
+  // see if the row is dominant
+  if (aRowFrame) {
+    GetColorAndStyle(aRowFrame, aTableWM, aSide, &tempBorder.style,
+                     &tempBorder.color, &tempBorder.width);
+    tempBorder.owner = aAja && inlineAxis ? eAjaRowOwner : eRowOwner;
+    border = CompareBorders(!CELL_CORNER, border, tempBorder, false);
+    if (StyleBorderStyle::Hidden == border.style) {
+      return border;
+    }
+  }
+  // see if the cell is dominant
+  if (aCellFrame) {
+    GetColorAndStyle(aCellFrame, aTableWM, aSide, &tempBorder.style,
+                     &tempBorder.color, &tempBorder.width);
+    tempBorder.owner = aAja ? eAjaCellOwner : eCellOwner;
+    border = CompareBorders(!CELL_CORNER, border, tempBorder, false);
+  }
+  return border;
+}
+
+static bool Perpendicular(mozilla::LogicalSide aSide1,
+                          mozilla::LogicalSide aSide2) {
+  return IsInline(aSide1) != IsInline(aSide2);
+}
+
+// Initial value indicating that BCCornerInfo's ownerStyle hasn't been set yet.
+#define BORDER_STYLE_UNSET static_cast<StyleBorderStyle>(255)
+
+struct BCCornerInfo {
+  BCCornerInfo() {
+    ownerColor = 0;
+    ownerWidth = subWidth = ownerElem = subSide = subElem = hasDashDot =
+        numSegs = bevel = 0;
+    ownerSide = eLogicalSideBStart;
+    ownerStyle = BORDER_STYLE_UNSET;
+    subStyle = StyleBorderStyle::Solid;
+  }
+
+  void Set(mozilla::LogicalSide aSide, BCCellBorder border);
+
+  void Update(mozilla::LogicalSide aSide, BCCellBorder border);
+
+  nscolor ownerColor;   // color of borderOwner
+  uint16_t ownerWidth;  // pixel width of borderOwner
+  uint16_t subWidth;    // pixel width of the largest border intersecting the
+                        // border perpendicular to ownerSide
+  StyleBorderStyle subStyle;    // border style of subElem
+  StyleBorderStyle ownerStyle;  // border style of ownerElem
+  uint16_t ownerSide : 2;  // LogicalSide (e.g eLogicalSideBStart, etc) of the
+                           // border owning the corner relative to the corner
+  uint16_t
+      ownerElem : 4;  // elem type (e.g. eTable, eGroup, etc) owning the corner
+  uint16_t subSide : 2;  // side of border with subWidth relative to the corner
+  uint16_t subElem : 4;  // elem type (e.g. eTable, eGroup, etc) of sub owner
+  uint16_t hasDashDot : 1;  // does a dashed, dotted segment enter the corner,
+                            // they cannot be beveled
+  uint16_t numSegs : 3;     // number of segments entering corner
+  uint16_t bevel : 1;       // is the corner beveled (uses the above two fields
+                            // together with subWidth)
+  // 7 bits are unused
+};
+
+// Start a new border at this corner, going in the direction of a given side.
+void BCCornerInfo::Set(mozilla::LogicalSide aSide, BCCellBorder aBorder) {
+  // FIXME bug 1508921: We mask 4-bit BCBorderOwner enum to 3 bits to preserve
+  // buggy behavior found by the frame_above_rules_all.html mochitest.
+  ownerElem = aBorder.owner & 0x7;
+
+  ownerStyle = aBorder.style;
+  ownerWidth = aBorder.width;
+  ownerColor = aBorder.color;
+  ownerSide = aSide;
+  hasDashDot = 0;
+  numSegs = 0;
+  if (aBorder.width > 0) {
+    numSegs++;
+    hasDashDot = (StyleBorderStyle::Dashed == aBorder.style) ||
+                 (StyleBorderStyle::Dotted == aBorder.style);
+  }
+  bevel = 0;
+  subWidth = 0;
+  // the following will get set later
+  subSide = IsInline(aSide) ? eLogicalSideBStart : eLogicalSideIStart;
+  subElem = eTableOwner;
+  subStyle = StyleBorderStyle::Solid;
+}
+
+// Add a new border going in the direction of a given side, and update the
+// dominant border.
+void BCCornerInfo::Update(mozilla::LogicalSide aSide, BCCellBorder aBorder) {
+  if (ownerStyle == BORDER_STYLE_UNSET) {
+    Set(aSide, aBorder);
+  } else {
+    bool isInline = IsInline(aSide);  // relative to the corner
+    BCCellBorder oldBorder, tempBorder;
+    oldBorder.owner = (BCBorderOwner)ownerElem;
+    oldBorder.style = ownerStyle;
+    oldBorder.width = ownerWidth;
+    oldBorder.color = ownerColor;
+
+    LogicalSide oldSide = LogicalSide(ownerSide);
+
+    bool existingWins = false;
+    tempBorder = CompareBorders(CELL_CORNER, oldBorder, aBorder, isInline,
+                                &existingWins);
+
+    ownerElem = tempBorder.owner;
+    ownerStyle = tempBorder.style;
+    ownerWidth = tempBorder.width;
+    ownerColor = tempBorder.color;
+    if (existingWins) {  // existing corner is dominant
+      if (::Perpendicular(LogicalSide(ownerSide), aSide)) {
+        // see if the new sub info replaces the old
+        BCCellBorder subBorder;
+        subBorder.owner = (BCBorderOwner)subElem;
+        subBorder.style = subStyle;
+        subBorder.width = subWidth;
+        subBorder.color = 0;  // we are not interested in subBorder color
+        bool firstWins;
+
+        tempBorder = CompareBorders(CELL_CORNER, subBorder, aBorder, isInline,
+                                    &firstWins);
+
+        subElem = tempBorder.owner;
+        subStyle = tempBorder.style;
+        subWidth = tempBorder.width;
+        if (!firstWins) {
+          subSide = aSide;
+        }
+      }
+    } else {  // input args are dominant
+      ownerSide = aSide;
+      if (::Perpendicular(oldSide, LogicalSide(ownerSide))) {
+        subElem = oldBorder.owner;
+        subStyle = oldBorder.style;
+        subWidth = oldBorder.width;
+        subSide = oldSide;
+      }
+    }
+    if (aBorder.width > 0) {
+      numSegs++;
+      if (!hasDashDot && ((StyleBorderStyle::Dashed == aBorder.style) ||
+                          (StyleBorderStyle::Dotted == aBorder.style))) {
+        hasDashDot = 1;
+      }
+    }
+
+    // bevel the corner if only two perpendicular non dashed/dotted segments
+    // enter the corner
+    bevel = (2 == numSegs) && (subWidth > 1) && (0 == hasDashDot);
+  }
+}
+
+struct BCCorners {
+  BCCorners(int32_t aNumCorners, int32_t aStartIndex);
+
+  BCCornerInfo& operator[](int32_t i) const {
+    NS_ASSERTION((i >= startIndex) && (i <= endIndex), "program error");
+    return corners[clamped(i, startIndex, endIndex) - startIndex];
+  }
+
+  int32_t startIndex;
+  int32_t endIndex;
+  UniquePtr<BCCornerInfo[]> corners;
+};
+
+BCCorners::BCCorners(int32_t aNumCorners, int32_t aStartIndex) {
+  NS_ASSERTION((aNumCorners > 0) && (aStartIndex >= 0), "program error");
+  startIndex = aStartIndex;
+  endIndex = aStartIndex + aNumCorners - 1;
+  corners = MakeUnique<BCCornerInfo[]>(aNumCorners);
+}
+
+struct BCCellBorders {
+  BCCellBorders(int32_t aNumBorders, int32_t aStartIndex);
+
+  BCCellBorder& operator[](int32_t i) const {
+    NS_ASSERTION((i >= startIndex) && (i <= endIndex), "program error");
+    return borders[clamped(i, startIndex, endIndex) - startIndex];
+  }
+
+  int32_t startIndex;
+  int32_t endIndex;
+  UniquePtr<BCCellBorder[]> borders;
+};
+
+BCCellBorders::BCCellBorders(int32_t aNumBorders, int32_t aStartIndex) {
+  NS_ASSERTION((aNumBorders > 0) && (aStartIndex >= 0), "program error");
+  startIndex = aStartIndex;
+  endIndex = aStartIndex + aNumBorders - 1;
+  borders = MakeUnique<BCCellBorder[]>(aNumBorders);
+}
+
+// this function sets the new border properties and returns true if the border
+// segment will start a new segment and not be accumulated into the previous
+// segment.
+static bool SetBorder(const BCCellBorder& aNewBorder, BCCellBorder& aBorder) {
+  bool changed = (aNewBorder.style != aBorder.style) ||
+                 (aNewBorder.width != aBorder.width) ||
+                 (aNewBorder.color != aBorder.color);
+  aBorder.color = aNewBorder.color;
+  aBorder.width = aNewBorder.width;
+  aBorder.style = aNewBorder.style;
+  aBorder.owner = aNewBorder.owner;
+
+  return changed;
+}
+
+// this function will set the inline-dir border. It will return true if the
+// existing segment will not be continued. Having a block-dir owner of a corner
+// should also start a new segment.
+static bool SetInlineDirBorder(const BCCellBorder& aNewBorder,
+                               const BCCornerInfo& aCorner,
+                               BCCellBorder& aBorder) {
+  bool startSeg = ::SetBorder(aNewBorder, aBorder);
+  if (!startSeg) {
+    startSeg = !IsInline(LogicalSide(aCorner.ownerSide));
+  }
+  return startSeg;
+}
+
+// Make the damage area larger on the top and bottom by at least one row and on
+// the left and right at least one column. This is done so that adjacent
+// elements are part of the border calculations. The extra segments and borders
+// outside the actual damage area will not be updated in the cell map, because
+// they in turn would need info from adjacent segments outside the damage area
+// to be accurate.
+void nsTableFrame::ExpandBCDamageArea(TableArea& aArea) const {
+  int32_t numRows = GetRowCount();
+  int32_t numCols = GetColCount();
+
+  int32_t dStartX = aArea.StartCol();
+  int32_t dEndX = aArea.EndCol() - 1;
+  int32_t dStartY = aArea.StartRow();
+  int32_t dEndY = aArea.EndRow() - 1;
+
+  // expand the damage area in each direction
+  if (dStartX > 0) {
+    dStartX--;
+  }
+  if (dEndX < (numCols - 1)) {
+    dEndX++;
+  }
+  if (dStartY > 0) {
+    dStartY--;
+  }
+  if (dEndY < (numRows - 1)) {
+    dEndY++;
+  }
+  // Check the damage area so that there are no cells spanning in or out. If
+  // there are any then make the damage area as big as the table, similarly to
+  // the way the cell map decides whether to rebuild versus expand. This could
+  // be optimized to expand to the smallest area that contains no spanners, but
+  // it may not be worth the effort in general, and it would need to be done in
+  // the cell map as well.
+  bool haveSpanner = false;
+  if ((dStartX > 0) || (dEndX < (numCols - 1)) || (dStartY > 0) ||
+      (dEndY < (numRows - 1))) {
+    nsTableCellMap* tableCellMap = GetCellMap();
+    if (!tableCellMap) ABORT0();
+    // Get the ordered row groups
+    RowGroupArray rowGroups = OrderedRowGroups();
+
+    // Scope outside loop to be used as hint.
+    nsCellMap* cellMap = nullptr;
+    for (uint32_t rgIdx = 0; rgIdx < rowGroups.Length(); rgIdx++) {
+      nsTableRowGroupFrame* rgFrame = rowGroups[rgIdx];
+      int32_t rgStartY = rgFrame->GetStartRowIndex();
+      int32_t rgEndY = rgStartY + rgFrame->GetRowCount() - 1;
+      if (dEndY < rgStartY) break;
+      cellMap = tableCellMap->GetMapFor(rgFrame, cellMap);
+      if (!cellMap) ABORT0();
+      // check for spanners from above and below
+      if ((dStartY > 0) && (dStartY >= rgStartY) && (dStartY <= rgEndY)) {
+        if (uint32_t(dStartY - rgStartY) >= cellMap->mRows.Length()) ABORT0();
+        const nsCellMap::CellDataArray& row =
+            cellMap->mRows[dStartY - rgStartY];
+        for (int32_t x = dStartX; x <= dEndX; x++) {
+          CellData* cellData = row.SafeElementAt(x);
+          if (cellData && (cellData->IsRowSpan())) {
+            haveSpanner = true;
+            break;
+          }
+        }
+        if (dEndY < rgEndY) {
+          if (uint32_t(dEndY + 1 - rgStartY) >= cellMap->mRows.Length())
+            ABORT0();
+          const nsCellMap::CellDataArray& row2 =
+              cellMap->mRows[dEndY + 1 - rgStartY];
+          for (int32_t x = dStartX; x <= dEndX; x++) {
+            CellData* cellData = row2.SafeElementAt(x);
+            if (cellData && (cellData->IsRowSpan())) {
+              haveSpanner = true;
+              break;
+            }
+          }
+        }
+      }
+      // check for spanners on the left and right
+      int32_t iterStartY;
+      int32_t iterEndY;
+      if ((dStartY >= rgStartY) && (dStartY <= rgEndY)) {
+        // the damage area starts in the row group
+        iterStartY = dStartY;
+        iterEndY = std::min(dEndY, rgEndY);
+      } else if ((dEndY >= rgStartY) && (dEndY <= rgEndY)) {
+        // the damage area ends in the row group
+        iterStartY = rgStartY;
+        iterEndY = dEndY;
+      } else if ((rgStartY >= dStartY) && (rgEndY <= dEndY)) {
+        // the damage area contains the row group
+        iterStartY = rgStartY;
+        iterEndY = rgEndY;
+      } else {
+        // the damage area does not overlap the row group
+        continue;
+      }
+      NS_ASSERTION(iterStartY >= 0 && iterEndY >= 0,
+                   "table index values are expected to be nonnegative");
+      for (int32_t y = iterStartY; y <= iterEndY; y++) {
+        if (uint32_t(y - rgStartY) >= cellMap->mRows.Length()) ABORT0();
+        const nsCellMap::CellDataArray& row = cellMap->mRows[y - rgStartY];
+        CellData* cellData = row.SafeElementAt(dStartX);
+        if (cellData && (cellData->IsColSpan())) {
+          haveSpanner = true;
+          break;
+        }
+        if (dEndX < (numCols - 1)) {
+          cellData = row.SafeElementAt(dEndX + 1);
+          if (cellData && (cellData->IsColSpan())) {
+            haveSpanner = true;
+            break;
+          }
+        }
+      }
+    }
+  }
+  if (haveSpanner) {
+    // make the damage area the whole table
+    aArea.StartCol() = 0;
+    aArea.StartRow() = 0;
+    aArea.ColCount() = numCols;
+    aArea.RowCount() = numRows;
+  } else {
+    aArea.StartCol() = dStartX;
+    aArea.StartRow() = dStartY;
+    aArea.ColCount() = 1 + dEndX - dStartX;
+    aArea.RowCount() = 1 + dEndY - dStartY;
+  }
+}
+
+#define ADJACENT true
+#define INLINE_DIR true
+
+void BCMapCellInfo::SetTableBStartBorderWidth(BCPixelSize aWidth) {
+  mTableBCData->mBStartBorderWidth =
+      std::max(mTableBCData->mBStartBorderWidth, aWidth);
+}
+
+void BCMapCellInfo::SetTableIStartBorderWidth(int32_t aRowB,
+                                              BCPixelSize aWidth) {
+  // update the iStart first cell border
+  if (aRowB == 0) {
+    mTableBCData->mIStartCellBorderWidth = aWidth;
+  }
+  mTableBCData->mIStartBorderWidth =
+      std::max(mTableBCData->mIStartBorderWidth, aWidth);
+}
+
+void BCMapCellInfo::SetTableIEndBorderWidth(int32_t aRowB, BCPixelSize aWidth) {
+  // update the iEnd first cell border
+  if (aRowB == 0) {
+    mTableBCData->mIEndCellBorderWidth = aWidth;
+  }
+  mTableBCData->mIEndBorderWidth =
+      std::max(mTableBCData->mIEndBorderWidth, aWidth);
+}
+
+void BCMapCellInfo::SetIEndBorderWidths(BCPixelSize aWidth) {
+  // update the borders of the cells and cols affected
+  if (mCell) {
+    mCell->SetBorderWidth(
+        eLogicalSideIEnd,
+        std::max(aWidth, mCell->GetBorderWidth(eLogicalSideIEnd)));
+  }
+  if (mEndCol) {
+    BCPixelSize half = BC_BORDER_START_HALF(aWidth);
+    mEndCol->SetIEndBorderWidth(std::max(half, mEndCol->GetIEndBorderWidth()));
+  }
+}
+
+void BCMapCellInfo::SetBEndBorderWidths(BCPixelSize aWidth) {
+  // update the borders of the affected cells and rows
+  if (mCell) {
+    mCell->SetBorderWidth(
+        eLogicalSideBEnd,
+        std::max(aWidth, mCell->GetBorderWidth(eLogicalSideBEnd)));
+  }
+  if (mEndRow) {
+    BCPixelSize half = BC_BORDER_START_HALF(aWidth);
+    mEndRow->SetBEndBCBorderWidth(
+        std::max(half, mEndRow->GetBEndBCBorderWidth()));
+  }
+}
+
+void BCMapCellInfo::SetBStartBorderWidths(BCPixelSize aWidth) {
+  if (mCell) {
+    mCell->SetBorderWidth(
+        eLogicalSideBStart,
+        std::max(aWidth, mCell->GetBorderWidth(eLogicalSideBStart)));
+  }
+  if (mStartRow) {
+    BCPixelSize half = BC_BORDER_END_HALF(aWidth);
+    mStartRow->SetBStartBCBorderWidth(
+        std::max(half, mStartRow->GetBStartBCBorderWidth()));
+  }
+}
+
+void BCMapCellInfo::SetIStartBorderWidths(BCPixelSize aWidth) {
+  if (mCell) {
+    mCell->SetBorderWidth(
+        eLogicalSideIStart,
+        std::max(aWidth, mCell->GetBorderWidth(eLogicalSideIStart)));
+  }
+  if (mStartCol) {
+    BCPixelSize half = BC_BORDER_END_HALF(aWidth);
+    mStartCol->SetIStartBorderWidth(
+        std::max(half, mStartCol->GetIStartBorderWidth()));
+  }
+}
+
+void BCMapCellInfo::SetTableBEndBorderWidth(BCPixelSize aWidth) {
+  mTableBCData->mBEndBorderWidth =
+      std::max(mTableBCData->mBEndBorderWidth, aWidth);
+}
+
+void BCMapCellInfo::SetColumn(int32_t aColX) {
+  mCurrentColFrame = mTableFirstInFlow->GetColFrame(aColX);
+  mCurrentColGroupFrame =
+      static_cast<nsTableColGroupFrame*>(mCurrentColFrame->GetParent());
+  if (!mCurrentColGroupFrame) {
+    NS_ERROR("null mCurrentColGroupFrame");
+  }
+}
+
+void BCMapCellInfo::IncrementRow(bool aResetToBStartRowOfCell) {
+  mCurrentRowFrame =
+      aResetToBStartRowOfCell ? mStartRow : mCurrentRowFrame->GetNextRow();
+}
+
+BCCellBorder BCMapCellInfo::GetBStartEdgeBorder() {
+  return CompareBorders(mTableFrame, mCurrentColGroupFrame, mCurrentColFrame,
+                        mRowGroup, mStartRow, mCell, mTableWM,
+                        eLogicalSideBStart, !ADJACENT);
+}
+
+BCCellBorder BCMapCellInfo::GetBEndEdgeBorder() {
+  return CompareBorders(mTableFrame, mCurrentColGroupFrame, mCurrentColFrame,
+                        mRowGroup, mEndRow, mCell, mTableWM, eLogicalSideBEnd,
+                        ADJACENT);
+}
+BCCellBorder BCMapCellInfo::GetIStartEdgeBorder() {
+  return CompareBorders(mTableFrame, mColGroup, mStartCol, mRowGroup,
+                        mCurrentRowFrame, mCell, mTableWM, eLogicalSideIStart,
+                        !ADJACENT);
+}
+BCCellBorder BCMapCellInfo::GetIEndEdgeBorder() {
+  return CompareBorders(mTableFrame, mColGroup, mEndCol, mRowGroup,
+                        mCurrentRowFrame, mCell, mTableWM, eLogicalSideIEnd,
+                        ADJACENT);
+}
+BCCellBorder BCMapCellInfo::GetIEndInternalBorder() {
+  const nsIFrame* cg = mCgAtEnd ? mColGroup : nullptr;
+  return CompareBorders(nullptr, cg, mEndCol, nullptr, nullptr, mCell, mTableWM,
+                        eLogicalSideIEnd, ADJACENT);
+}
+
+BCCellBorder BCMapCellInfo::GetIStartInternalBorder() {
+  const nsIFrame* cg = mCgAtStart ? mColGroup : nullptr;
+  return CompareBorders(nullptr, cg, mStartCol, nullptr, nullptr, mCell,
+                        mTableWM, eLogicalSideIStart, !ADJACENT);
+}
+
+BCCellBorder BCMapCellInfo::GetBEndInternalBorder() {
+  const nsIFrame* rg = mRgAtEnd ? mRowGroup : nullptr;
+  return CompareBorders(nullptr, nullptr, nullptr, rg, mEndRow, mCell, mTableWM,
+                        eLogicalSideBEnd, ADJACENT);
+}
+
+BCCellBorder BCMapCellInfo::GetBStartInternalBorder() {
+  const nsIFrame* rg = mRgAtStart ? mRowGroup : nullptr;
+  return CompareBorders(nullptr, nullptr, nullptr, rg, mStartRow, mCell,
+                        mTableWM, eLogicalSideBStart, !ADJACENT);
+}
+
+//  Calculate border information for border-collapsed tables.
+//  Because borders of table/row/cell, etc merge into one, we need to
+//  determine which border dominates at each cell. In addition, corner-specific
+//  information, e.g. bevelling, is computed as well.
+//
+//  Here is the order for storing border edges in the cell map as a cell is
+//  processed.
+//
+//  For each cell, at least 4 edges are processed:
+//  * There are colspan * N block-start and block-end edges.
+//  * There are rowspan * N inline-start and inline-end edges.
+//
+//  1) If the cell being processed is at the block-start of the table, store the
+//     block-start edge.
+//  2) If the cell being processed is at the inline-start of the table, store
+//  the
+//     inline-start edge.
+//  3) Store the inline-end edge.
+//  4) Store the block-end edge.
+//
+//  These steps are traced by calls to `SetBCBorderEdge`.
+//
+//  Corners are indexed by columns only, to avoid allocating a full row * col
+//  array of `BCCornerInfo`. This trades off memory allocation versus moving
+//  previous corner information around.
+//
+//  For each cell:
+//  1) If the cell is at the block-start of the table, but not at the
+//  inline-start of the table, store its block-start inline-start corner.
+//
+//  2) If the cell is at the inline-start of the table, store the block-start
+//  inline-start corner.
+//
+//  3) If the cell is at the block-start inline-end of the table, or not at the
+//  block-start of the table, store the block-start inline-end corner.
+//
+//  4) If the cell is at the block-end inline-end of the table, store the
+//  block-end inline-end corner.
+//
+//  5) If the cell is at the block-end of the table, store the block-end
+//  inline-start.
+//
+//  Visually, it looks like this:
+//
+//  2--1--1--1--1--1--3
+//  |  |  |  |  |  |  |
+//  2--3--3--3--3--3--3
+//  |  |  |  |  |  |  |
+//  2--3--3--3--3--3--3
+//  |  |  |  |  |  |  |
+//  5--5--5--5--5--5--4
+//
+//  For rowspan/colspan cells, the latest border information is propagated
+//  along its "corners".
+//
+//  These steps are traced by calls to `SetBCBorderCorner`.
+void nsTableFrame::CalcBCBorders() {
+  NS_ASSERTION(IsBorderCollapse(),
+               "calling CalcBCBorders on separated-border table");
+  nsTableCellMap* tableCellMap = GetCellMap();
+  if (!tableCellMap) ABORT0();
+  int32_t numRows = GetRowCount();
+  int32_t numCols = GetColCount();
+  if (!numRows || !numCols) return;  // nothing to do
+
+  // Get the property holding the table damage area and border widths
+  TableBCData* propData = GetTableBCData();
+  if (!propData) ABORT0();
+
+  TableArea damageArea(propData->mDamageArea);
+  // See documentation for why we do this.
+  ExpandBCDamageArea(damageArea);
+
+  // We accumulate border widths as we process the cells, so we need
+  // to reset it once in the beginning.
+  bool tableBorderReset[4];
+  for (uint32_t sideX = 0; sideX < ArrayLength(tableBorderReset); sideX++) {
+    tableBorderReset[sideX] = false;
+  }
+
+  // Storage for block-direction borders from the previous row, indexed by
+  // columns.
+  BCCellBorders lastBlockDirBorders(damageArea.ColCount() + 1,
+                                    damageArea.StartCol());
+  if (!lastBlockDirBorders.borders) ABORT0();
+  // Inline direction border at block start of the table, computed by the
+  // previous cell. Unused afterwards.
+  Maybe<BCCellBorder> firstRowBStartEdgeBorder;
+  BCCellBorder lastBEndBorder;
+  // Storage for inline-direction borders from previous cells, indexed by
+  // columns.
+  // TODO(dshin): Why ColCount + 1? Number of inline segments should match
+  // column count exactly, unlike block direction segments...
+  BCCellBorders lastBEndBorders(damageArea.ColCount() + 1,
+                                damageArea.StartCol());
+  if (!lastBEndBorders.borders) ABORT0();
+
+  BCMapCellInfo info(this);
+
+  // Block-start corners of the cell being traversed, indexed by columns.
+  BCCorners bStartCorners(damageArea.ColCount() + 1, damageArea.StartCol());
+  if (!bStartCorners.corners) ABORT0();
+  // Block-end corners of the cell being traversed, indexed by columns.
+  // Note that when a new row starts, they become block-start corners and used
+  // as such, until cleared with `Set`.
+  BCCorners bEndCorners(damageArea.ColCount() + 1, damageArea.StartCol());
+  if (!bEndCorners.corners) ABORT0();
+
+  BCMapCellIterator iter(this, damageArea);
+  for (iter.First(info); !iter.mAtEnd; iter.Next(info)) {
+    // see if firstRowBStartEdgeBorder, lastBEndBorder need to be reset
+    if (iter.IsNewRow()) {
+      if (info.mRowIndex == 0) {
+        BCCellBorder border;
+        border.Reset(info.mRowIndex, info.mRowSpan);
+        firstRowBStartEdgeBorder = Some(border);
+      } else {
+        firstRowBStartEdgeBorder = Nothing{};
+      }
+      lastBEndBorder.Reset(info.GetCellEndRowIndex() + 1, info.mRowSpan);
+    } else if (info.mColIndex > damageArea.StartCol()) {
+      lastBEndBorder = lastBEndBorders[info.mColIndex - 1];
+      if (lastBEndBorder.rowIndex > (info.GetCellEndRowIndex() + 1)) {
+        // the bEnd border's iStart edge butts against the middle of a rowspan
+        lastBEndBorder.Reset(info.GetCellEndRowIndex() + 1, info.mRowSpan);
+      }
+    }
+
+    // find the dominant border considering the cell's bStart border and the
+    // table, row group, row if the border is at the bStart of the table,
+    // otherwise it was processed in a previous row
+    if (0 == info.mRowIndex) {
+      if (!tableBorderReset[eLogicalSideBStart]) {
+        propData->mBStartBorderWidth = 0;
+        tableBorderReset[eLogicalSideBStart] = true;
+      }
+      for (int32_t colIdx = info.mColIndex; colIdx <= info.GetCellEndColIndex();
+           colIdx++) {
+        info.SetColumn(colIdx);
+        BCCellBorder currentBorder = info.GetBStartEdgeBorder();
+        BCCornerInfo& bStartIStartCorner = bStartCorners[colIdx];
+        // Mark inline-end direction border from this corner.
+        if (0 == colIdx) {
+          bStartIStartCorner.Set(eLogicalSideIEnd, currentBorder);
+        } else {
+          bStartIStartCorner.Update(eLogicalSideIEnd, currentBorder);
+          tableCellMap->SetBCBorderCorner(
+              eLogicalCornerBStartIStart, *iter.mCellMap, 0, 0, colIdx,
+              LogicalSide(bStartIStartCorner.ownerSide),
+              bStartIStartCorner.subWidth, bStartIStartCorner.bevel);
+        }
+        // Above, we set the corner `colIndex` column as having a border towards
+        // inline-end, heading towards the next column. Vice versa is also true,
+        // where the next column has a border heading towards this column.
+        bStartCorners[colIdx + 1].Set(eLogicalSideIStart, currentBorder);
+        MOZ_ASSERT(firstRowBStartEdgeBorder,
+                   "Inline start border tracking not set?");
+        // update firstRowBStartEdgeBorder and see if a new segment starts
+        bool startSeg =
+            firstRowBStartEdgeBorder
+                ? SetInlineDirBorder(currentBorder, bStartIStartCorner,
+                                     firstRowBStartEdgeBorder.ref())
+                : true;
+        // store the border segment in the cell map
+        tableCellMap->SetBCBorderEdge(eLogicalSideBStart, *iter.mCellMap, 0, 0,
+                                      colIdx, 1, currentBorder.owner,
+                                      currentBorder.width, startSeg);
+
+        // Set border width at block-start (table-wide and for the cell), but
+        // only if it's the largest we've encountered.
+        info.SetTableBStartBorderWidth(currentBorder.width);
+        info.SetBStartBorderWidths(currentBorder.width);
+      }
+    } else {
+      // see if the bStart border needs to be the start of a segment due to a
+      // block-dir border owning the corner
+      if (info.mColIndex > 0) {
+        BCData& data = info.mCellData->mData;
+        if (!data.IsBStartStart()) {
+          LogicalSide cornerSide;
+          bool bevel;
+          data.GetCorner(cornerSide, bevel);
+          if (IsBlock(cornerSide)) {
+            data.SetBStartStart(true);
+          }
+        }
+      }
+    }
+
+    // find the dominant border considering the cell's iStart border and the
+    // table, col group, col if the border is at the iStart of the table,
+    // otherwise it was processed in a previous col
+    if (0 == info.mColIndex) {
+      if (!tableBorderReset[eLogicalSideIStart]) {
+        propData->mIStartBorderWidth = 0;
+        tableBorderReset[eLogicalSideIStart] = true;
+      }
+      info.mCurrentRowFrame = nullptr;
+      for (int32_t rowB = info.mRowIndex; rowB <= info.GetCellEndRowIndex();
+           rowB++) {
+        info.IncrementRow(rowB == info.mRowIndex);
+        BCCellBorder currentBorder = info.GetIStartEdgeBorder();
+        BCCornerInfo& bStartIStartCorner =
+            (0 == rowB) ? bStartCorners[0] : bEndCorners[0];
+        bStartIStartCorner.Update(eLogicalSideBEnd, currentBorder);
+        tableCellMap->SetBCBorderCorner(
+            eLogicalCornerBStartIStart, *iter.mCellMap, iter.mRowGroupStart,
+            rowB, 0, LogicalSide(bStartIStartCorner.ownerSide),
+            bStartIStartCorner.subWidth, bStartIStartCorner.bevel);
+        bEndCorners[0].Set(eLogicalSideBStart, currentBorder);
+
+        // update lastBlockDirBorders and see if a new segment starts
+        bool startSeg = SetBorder(currentBorder, lastBlockDirBorders[0]);
+        // store the border segment in the cell map
+        tableCellMap->SetBCBorderEdge(eLogicalSideIStart, *iter.mCellMap,
+                                      iter.mRowGroupStart, rowB, info.mColIndex,
+                                      1, currentBorder.owner,
+                                      currentBorder.width, startSeg);
+        // Set border width at inline-start (table-wide and for the cell), but
+        // only if it's the largest we've encountered.
+        info.SetTableIStartBorderWidth(rowB, currentBorder.width);
+        info.SetIStartBorderWidths(currentBorder.width);
+      }
+    }
+
+    // find the dominant border considering the cell's iEnd border, adjacent
+    // cells and the table, row group, row
+    if (info.mNumTableCols == info.GetCellEndColIndex() + 1) {
+      // touches iEnd edge of table
+      if (!tableBorderReset[eLogicalSideIEnd]) {
+        propData->mIEndBorderWidth = 0;
+        tableBorderReset[eLogicalSideIEnd] = true;
+      }
+      info.mCurrentRowFrame = nullptr;
+      for (int32_t rowB = info.mRowIndex; rowB <= info.GetCellEndRowIndex();
+           rowB++) {
+        info.IncrementRow(rowB == info.mRowIndex);
+        BCCellBorder currentBorder = info.GetIEndEdgeBorder();
+        // Update/store the bStart-iEnd & bEnd-iEnd corners. Note that we
+        // overwrite all corner information to the end of the column span.
+        BCCornerInfo& bStartIEndCorner =
+            (0 == rowB) ? bStartCorners[info.GetCellEndColIndex() + 1]
+                        : bEndCorners[info.GetCellEndColIndex() + 1];
+        bStartIEndCorner.Update(eLogicalSideBEnd, currentBorder);
+        tableCellMap->SetBCBorderCorner(
+            eLogicalCornerBStartIEnd, *iter.mCellMap, iter.mRowGroupStart, rowB,
+            info.GetCellEndColIndex(), LogicalSide(bStartIEndCorner.ownerSide),
+            bStartIEndCorner.subWidth, bStartIEndCorner.bevel);
+        BCCornerInfo& bEndIEndCorner =
+            bEndCorners[info.GetCellEndColIndex() + 1];
+        bEndIEndCorner.Set(eLogicalSideBStart, currentBorder);
+        tableCellMap->SetBCBorderCorner(
+            eLogicalCornerBEndIEnd, *iter.mCellMap, iter.mRowGroupStart, rowB,
+            info.GetCellEndColIndex(), LogicalSide(bEndIEndCorner.ownerSide),
+            bEndIEndCorner.subWidth, bEndIEndCorner.bevel);
+        // update lastBlockDirBorders and see if a new segment starts
+        bool startSeg = SetBorder(
+            currentBorder, lastBlockDirBorders[info.GetCellEndColIndex() + 1]);
+        // store the border segment in the cell map and update cellBorders
+        tableCellMap->SetBCBorderEdge(
+            eLogicalSideIEnd, *iter.mCellMap, iter.mRowGroupStart, rowB,
+            info.GetCellEndColIndex(), 1, currentBorder.owner,
+            currentBorder.width, startSeg);
+        // Set border width at inline-end (table-wide and for the cell), but
+        // only if it's the largest we've encountered.
+        info.SetTableIEndBorderWidth(rowB, currentBorder.width);
+        info.SetIEndBorderWidths(currentBorder.width);
+      }
+    } else {
+      // Cell entries, but not on the block-end side of the entire table.
+      int32_t segLength = 0;
+      BCMapCellInfo ajaInfo(this);
+      BCMapCellInfo priorAjaInfo(this);
+      for (int32_t rowB = info.mRowIndex; rowB <= info.GetCellEndRowIndex();
+           rowB += segLength) {
+        // Grab the cell adjacent to our inline-end.
+        iter.PeekIEnd(info, rowB, ajaInfo);
+        BCCellBorder currentBorder = info.GetIEndInternalBorder();
+        BCCellBorder adjacentBorder = ajaInfo.GetIStartInternalBorder();
+        currentBorder = CompareBorders(!CELL_CORNER, currentBorder,
+                                       adjacentBorder, !INLINE_DIR);
+
+        segLength = std::max(1, ajaInfo.mRowIndex + ajaInfo.mRowSpan - rowB);
+        segLength = std::min(segLength, info.mRowIndex + info.mRowSpan - rowB);
+
+        // update lastBlockDirBorders and see if a new segment starts
+        bool startSeg = SetBorder(
+            currentBorder, lastBlockDirBorders[info.GetCellEndColIndex() + 1]);
+        // store the border segment in the cell map and update cellBorders
+        if (info.GetCellEndColIndex() < damageArea.EndCol() &&
+            rowB >= damageArea.StartRow() && rowB < damageArea.EndRow()) {
+          tableCellMap->SetBCBorderEdge(
+              eLogicalSideIEnd, *iter.mCellMap, iter.mRowGroupStart, rowB,
+              info.GetCellEndColIndex(), segLength, currentBorder.owner,
+              currentBorder.width, startSeg);
+          info.SetIEndBorderWidths(currentBorder.width);
+          ajaInfo.SetIStartBorderWidths(currentBorder.width);
+        }
+        // Does the block-start inline-end corner hit the inline-end adjacent
+        // cell that wouldn't have an inline border? e.g.
+        //
+        // o-----------o---------------o
+        // |           |               |
+        // o-----------x Adjacent cell o
+        // | This Cell |   (rowspan)   |
+        // o-----------o---------------o
+        bool hitsSpanOnIEnd = (rowB > ajaInfo.mRowIndex) &&
+                              (rowB < ajaInfo.mRowIndex + ajaInfo.mRowSpan);
+        BCCornerInfo* bStartIEndCorner =
+            ((0 == rowB) || hitsSpanOnIEnd)
+                ? &bStartCorners[info.GetCellEndColIndex() + 1]
+                : &bEndCorners[info.GetCellEndColIndex() +
+                               1];  // From previous row.
+        bStartIEndCorner->Update(eLogicalSideBEnd, currentBorder);
+        // If this is a rowspan, need to consider if this "corner" is generating
+        // an inline segment for the adjacent cell. e.g.
+        //
+        // o--------------o----o
+        // |              |    |
+        // o              x----o
+        // | (This "row") |    |
+        // o--------------o----o
+        if (rowB != info.mRowIndex) {
+          currentBorder = priorAjaInfo.GetBEndInternalBorder();
+          BCCellBorder adjacentBorder = ajaInfo.GetBStartInternalBorder();
+          currentBorder = CompareBorders(!CELL_CORNER, currentBorder,
+                                         adjacentBorder, INLINE_DIR);
+          bStartIEndCorner->Update(eLogicalSideIEnd, currentBorder);
+        }
+        // Check that the spanned area is inside of the invalidation area
+        if (info.GetCellEndColIndex() < damageArea.EndCol() &&
+            rowB >= damageArea.StartRow()) {
+          if (0 != rowB) {
+            // Ok, actually store the information
+            tableCellMap->SetBCBorderCorner(
+                eLogicalCornerBStartIEnd, *iter.mCellMap, iter.mRowGroupStart,
+                rowB, info.GetCellEndColIndex(),
+                LogicalSide(bStartIEndCorner->ownerSide),
+                bStartIEndCorner->subWidth, bStartIEndCorner->bevel);
+          }
+          // Propagate this segment down the rowspan
+          for (int32_t rX = rowB + 1; rX < rowB + segLength; rX++) {
+            tableCellMap->SetBCBorderCorner(
+                eLogicalCornerBEndIEnd, *iter.mCellMap, iter.mRowGroupStart, rX,
+                info.GetCellEndColIndex(),
+                LogicalSide(bStartIEndCorner->ownerSide),
+                bStartIEndCorner->subWidth, false);
+          }
+        }
+        hitsSpanOnIEnd =
+            (rowB + segLength < ajaInfo.mRowIndex + ajaInfo.mRowSpan);
+        BCCornerInfo& bEndIEndCorner =
+            (hitsSpanOnIEnd) ? bStartCorners[info.GetCellEndColIndex() + 1]
+                             : bEndCorners[info.GetCellEndColIndex() + 1];
+        bEndIEndCorner.Set(eLogicalSideBStart, currentBorder);
+        priorAjaInfo = ajaInfo;
+      }
+    }
+    for (int32_t colIdx = info.mColIndex + 1;
+         colIdx <= info.GetCellEndColIndex(); colIdx++) {
+      lastBlockDirBorders[colIdx].Reset(0, 1);
+    }
+
+    // find the dominant border considering the cell's bEnd border, adjacent
+    // cells and the table, row group, row
+    if (info.mNumTableRows == info.GetCellEndRowIndex() + 1) {
+      // touches bEnd edge of table
+      if (!tableBorderReset[eLogicalSideBEnd]) {
+        propData->mBEndBorderWidth = 0;
+        tableBorderReset[eLogicalSideBEnd] = true;
+      }
+      for (int32_t colIdx = info.mColIndex; colIdx <= info.GetCellEndColIndex();
+           colIdx++) {
+        info.SetColumn(colIdx);
+        BCCellBorder currentBorder = info.GetBEndEdgeBorder();
+        BCCornerInfo& bEndIStartCorner = bEndCorners[colIdx];
+        bEndIStartCorner.Update(eLogicalSideIEnd, currentBorder);
+        tableCellMap->SetBCBorderCorner(
+            eLogicalCornerBEndIStart, *iter.mCellMap, iter.mRowGroupStart,
+            info.GetCellEndRowIndex(), colIdx,
+            LogicalSide(bEndIStartCorner.ownerSide), bEndIStartCorner.subWidth,
+            bEndIStartCorner.bevel);
+        BCCornerInfo& bEndIEndCorner = bEndCorners[colIdx + 1];
+        bEndIEndCorner.Update(eLogicalSideIStart, currentBorder);
+        // Store the block-end inline-end corner if it also is the block-end
+        // inline-end of the overall table.
+        if (info.mNumTableCols == colIdx + 1) {
+          tableCellMap->SetBCBorderCorner(
+              eLogicalCornerBEndIEnd, *iter.mCellMap, iter.mRowGroupStart,
+              info.GetCellEndRowIndex(), colIdx,
+              LogicalSide(bEndIEndCorner.ownerSide), bEndIEndCorner.subWidth,
+              bEndIEndCorner.bevel, true);
+        }
+        // update lastBEndBorder and see if a new segment starts
+        bool startSeg =
+            SetInlineDirBorder(currentBorder, bEndIStartCorner, lastBEndBorder);
+        if (!startSeg) {
+          // make sure that we did not compare apples to oranges i.e. the
+          // current border should be a continuation of the lastBEndBorder,
+          // as it is a bEnd border
+          // add 1 to the info.GetCellEndRowIndex()
+          startSeg =
+              (lastBEndBorder.rowIndex != (info.GetCellEndRowIndex() + 1));
+        }
+        // store the border segment in the cell map and update cellBorders
+        tableCellMap->SetBCBorderEdge(
+            eLogicalSideBEnd, *iter.mCellMap, iter.mRowGroupStart,
+            info.GetCellEndRowIndex(), colIdx, 1, currentBorder.owner,
+            currentBorder.width, startSeg);
+        // update lastBEndBorders
+        lastBEndBorder.rowIndex = info.GetCellEndRowIndex() + 1;
+        lastBEndBorder.rowSpan = info.mRowSpan;
+        lastBEndBorders[colIdx] = lastBEndBorder;
+
+        // Set border width at block-end (table-wide and for the cell), but
+        // only if it's the largest we've encountered.
+        info.SetBEndBorderWidths(currentBorder.width);
+        info.SetTableBEndBorderWidth(currentBorder.width);
+      }
+    } else {
+      int32_t segLength = 0;
+      BCMapCellInfo ajaInfo(this);
+      for (int32_t colIdx = info.mColIndex; colIdx <= info.GetCellEndColIndex();
+           colIdx += segLength) {
+        // Grab the cell adjacent to our block-end.
+        iter.PeekBEnd(info, colIdx, ajaInfo);
+        BCCellBorder currentBorder = info.GetBEndInternalBorder();
+        BCCellBorder adjacentBorder = ajaInfo.GetBStartInternalBorder();
+        currentBorder = CompareBorders(!CELL_CORNER, currentBorder,
+                                       adjacentBorder, INLINE_DIR);
+        segLength = std::max(1, ajaInfo.mColIndex + ajaInfo.mColSpan - colIdx);
+        segLength =
+            std::min(segLength, info.mColIndex + info.mColSpan - colIdx);
+
+        BCCornerInfo& bEndIStartCorner = bEndCorners[colIdx];
+        // e.g.
+        // o--o----------o
+        // |  | This col |
+        // o--x----------o
+        // |  Adjacent   |
+        // o--o----------o
+        bool hitsSpanBelow = (colIdx > ajaInfo.mColIndex) &&
+                             (colIdx < ajaInfo.mColIndex + ajaInfo.mColSpan);
+        bool update = true;
+        if (colIdx == info.mColIndex && colIdx > damageArea.StartCol()) {
+          int32_t prevRowIndex = lastBEndBorders[colIdx - 1].rowIndex;
+          if (prevRowIndex > info.GetCellEndRowIndex() + 1) {
+            // hits a rowspan on the iEnd side
+            update = false;
+            // the corner was taken care of during the cell on the iStart side
+          } else if (prevRowIndex < info.GetCellEndRowIndex() + 1) {
+            // spans below the cell to the iStart side
+            bStartCorners[colIdx] = bEndIStartCorner;
+            bEndIStartCorner.Set(eLogicalSideIEnd, currentBorder);
+            update = false;
+          }
+        }
+        if (update) {
+          bEndIStartCorner.Update(eLogicalSideIEnd, currentBorder);
+        }
+        // Check that the spanned area is inside of the invalidation area
+        if (info.GetCellEndRowIndex() < damageArea.EndRow() &&
+            colIdx >= damageArea.StartCol()) {
+          if (hitsSpanBelow) {
+            tableCellMap->SetBCBorderCorner(
+                eLogicalCornerBEndIStart, *iter.mCellMap, iter.mRowGroupStart,
+                info.GetCellEndRowIndex(), colIdx,
+                LogicalSide(bEndIStartCorner.ownerSide),
+                bEndIStartCorner.subWidth, bEndIStartCorner.bevel);
+          }
+          // Propagate this segment down the colspan
+          for (int32_t c = colIdx + 1; c < colIdx + segLength; c++) {
+            BCCornerInfo& corner = bEndCorners[c];
+            corner.Set(eLogicalSideIEnd, currentBorder);
+            tableCellMap->SetBCBorderCorner(
+                eLogicalCornerBEndIStart, *iter.mCellMap, iter.mRowGroupStart,
+                info.GetCellEndRowIndex(), c, LogicalSide(corner.ownerSide),
+                corner.subWidth, false);
+          }
+        }
+        // update lastBEndBorders and see if a new segment starts
+        bool startSeg =
+            SetInlineDirBorder(currentBorder, bEndIStartCorner, lastBEndBorder);
+        if (!startSeg) {
+          // make sure that we did not compare apples to oranges i.e. the
+          // current border should be a continuation of the lastBEndBorder,
+          // as it is a bEnd border
+          // add 1 to the info.GetCellEndRowIndex()
+          startSeg = (lastBEndBorder.rowIndex != info.GetCellEndRowIndex() + 1);
+        }
+        lastBEndBorder.rowIndex = info.GetCellEndRowIndex() + 1;
+        lastBEndBorder.rowSpan = info.mRowSpan;
+        for (int32_t c = colIdx; c < colIdx + segLength; c++) {
+          lastBEndBorders[c] = lastBEndBorder;
+        }
+
+        // store the border segment the cell map and update cellBorders
+        if (info.GetCellEndRowIndex() < damageArea.EndRow() &&
+            colIdx >= damageArea.StartCol() && colIdx < damageArea.EndCol()) {
+          tableCellMap->SetBCBorderEdge(
+              eLogicalSideBEnd, *iter.mCellMap, iter.mRowGroupStart,
+              info.GetCellEndRowIndex(), colIdx, segLength, currentBorder.owner,
+              currentBorder.width, startSeg);
+          info.SetBEndBorderWidths(currentBorder.width);
+          ajaInfo.SetBStartBorderWidths(currentBorder.width);
+        }
+        // update bEnd-iEnd corner
+        BCCornerInfo& bEndIEndCorner = bEndCorners[colIdx + segLength];
+        bEndIEndCorner.Update(eLogicalSideIStart, currentBorder);
+      }
+    }
+    // o------o------o
+    // |  c1  |      |
+    // o------o  c2  o
+    // |  c3  |      |
+    // o--e1--o--e2--o
+    // We normally join edges of successive block-end inline segments by
+    // consulting the previous segment; however, cell c2's block-end inline
+    // segment e2 is processed before e1, so we need to process such joins
+    // out-of-band here, when we're processing c3.
+    const auto nextColIndex = info.GetCellEndColIndex() + 1;
+    if ((info.mNumTableCols != nextColIndex) &&
+        (lastBEndBorders[nextColIndex].rowSpan > 1) &&
+        (lastBEndBorders[nextColIndex].rowIndex ==
+         info.GetCellEndRowIndex() + 1)) {
+      BCCornerInfo& corner = bEndCorners[nextColIndex];
+      if (!IsBlock(LogicalSide(corner.ownerSide))) {
+        // not a block-dir owner
+        BCCellBorder& thisBorder = lastBEndBorder;
+        BCCellBorder& nextBorder = lastBEndBorders[info.mColIndex + 1];
+        if ((thisBorder.color == nextBorder.color) &&
+            (thisBorder.width == nextBorder.width) &&
+            (thisBorder.style == nextBorder.style)) {
+          // set the flag on the next border indicating it is not the start of a
+          // new segment
+          if (iter.mCellMap) {
+            tableCellMap->ResetBStartStart(
+                eLogicalSideBEnd, *iter.mCellMap, iter.mRowGroupStart,
+                info.GetCellEndRowIndex(), nextColIndex);
+          }
+        }
+      }
+    }
+  }  // for (iter.First(info); info.mCell; iter.Next(info)) {
+  // reset the bc flag and damage area
+  SetNeedToCalcBCBorders(false);
+  propData->mDamageArea = TableArea(0, 0, 0, 0);
+#ifdef DEBUG_TABLE_CELLMAP
+  mCellMap->Dump();
+#endif
+}
+
+class BCPaintBorderIterator;
+
+struct BCBorderParameters {
+  StyleBorderStyle mBorderStyle;
+  nscolor mBorderColor;
+  nsRect mBorderRect;
+  int32_t mAppUnitsPerDevPixel;
+  mozilla::Side mStartBevelSide;
+  nscoord mStartBevelOffset;
+  mozilla::Side mEndBevelSide;
+  nscoord mEndBevelOffset;
+  bool mBackfaceIsVisible;
+
+  bool NeedToBevel() const {
+    if (!mStartBevelOffset && !mEndBevelOffset) {
+      return false;
+    }
+
+    if (mBorderStyle == StyleBorderStyle::Dashed ||
+        mBorderStyle == StyleBorderStyle::Dotted) {
+      return false;
+    }
+
+    return true;
+  }
+};
+
+struct BCBlockDirSeg {
+  BCBlockDirSeg();
+
+  void Start(BCPaintBorderIterator& aIter, BCBorderOwner aBorderOwner,
+             BCPixelSize aBlockSegISize, BCPixelSize aInlineSegBSize,
+             Maybe<nscoord> aEmptyRowEndSize);
+
+  void Initialize(BCPaintBorderIterator& aIter);
+  void GetBEndCorner(BCPaintBorderIterator& aIter, BCPixelSize aInlineSegBSize);
+
+  Maybe<BCBorderParameters> BuildBorderParameters(BCPaintBorderIterator& aIter,
+                                                  BCPixelSize aInlineSegBSize);
+  void Paint(BCPaintBorderIterator& aIter, DrawTarget& aDrawTarget,
+             BCPixelSize aInlineSegBSize);
+  void CreateWebRenderCommands(BCPaintBorderIterator& aIter,
+                               BCPixelSize aInlineSegBSize,
+                               wr::DisplayListBuilder& aBuilder,
+                               const layers::StackingContextHelper& aSc,
+                               const nsPoint& aPt);
+  void AdvanceOffsetB();
+  void IncludeCurrentBorder(BCPaintBorderIterator& aIter);
+
+  union {
+    nsTableColFrame* mCol;
+    int32_t mColWidth;
+  };
+  nscoord mOffsetI;    // i-offset with respect to the table edge
+  nscoord mOffsetB;    // b-offset with respect to the table edge
+  nscoord mLength;     // block-dir length including corners
+  BCPixelSize mWidth;  // thickness in pixels
+
+  nsTableCellFrame* mAjaCell;    // previous sibling to the first cell
+                                 // where the segment starts, it can be
+                                 // the owner of a segment
+  nsTableCellFrame* mFirstCell;  // cell at the start of the segment
+  nsTableRowGroupFrame*
+      mFirstRowGroup;           // row group at the start of the segment
+  nsTableRowFrame* mFirstRow;   // row at the start of the segment
+  nsTableCellFrame* mLastCell;  // cell at the current end of the
+                                // segment
+
+  uint8_t mOwner;                   // owner of the border, defines the
+                                    // style
+  LogicalSide mBStartBevelSide;     // direction to bevel at the bStart
+  nscoord mBStartBevelOffset;       // how much to bevel at the bStart
+  BCPixelSize mBEndInlineSegBSize;  // bSize of the crossing
+                                    // inline-dir border
+  nscoord mBEndOffset;              // how much longer is the segment due
+                                    // to the inline-dir border, by this
+                                    // amount the next segment needs to be
+                                    // shifted.
+  bool mIsBEndBevel;                // should we bevel at the bEnd
+};
+
+struct BCInlineDirSeg {
+  BCInlineDirSeg();
+
+  void Start(BCPaintBorderIterator& aIter, BCBorderOwner aBorderOwner,
+             BCPixelSize aBEndBlockSegISize, BCPixelSize aInlineSegBSize);
+  void GetIEndCorner(BCPaintBorderIterator& aIter, BCPixelSize aIStartSegISize);
+  void AdvanceOffsetI();
+  void IncludeCurrentBorder(BCPaintBorderIterator& aIter);
+  Maybe<BCBorderParameters> BuildBorderParameters(BCPaintBorderIterator& aIter);
+  void Paint(BCPaintBorderIterator& aIter, DrawTarget& aDrawTarget);
+  void CreateWebRenderCommands(BCPaintBorderIterator& aIter,
+                               wr::DisplayListBuilder& aBuilder,
+                               const layers::StackingContextHelper& aSc,
+                               const nsPoint& aPt);
+
+  nscoord mOffsetI;              // i-offset with respect to the table edge
+  nscoord mOffsetB;              // b-offset with respect to the table edge
+  nscoord mLength;               // inline-dir length including corners
+  BCPixelSize mWidth;            // border thickness in pixels
+  nscoord mIStartBevelOffset;    // how much to bevel at the iStart
+  LogicalSide mIStartBevelSide;  // direction to bevel at the iStart
+  bool mIsIEndBevel;             // should we bevel at the iEnd end
+  nscoord mIEndBevelOffset;      // how much to bevel at the iEnd
+  LogicalSide mIEndBevelSide;    // direction to bevel at the iEnd
+  nscoord mEndOffset;            // how much longer is the segment due
+                                 // to the block-dir border, by this
+                                 // amount the next segment needs to be
+                                 // shifted.
+  uint8_t mOwner;                // owner of the border, defines the
+                                 // style
+  nsTableCellFrame* mFirstCell;  // cell at the start of the segment
+  nsTableCellFrame* mAjaCell;    // neighboring cell to the first cell
+                                 // where the segment starts, it can be
+                                 // the owner of a segment
+};
+
+struct BCPaintData {
+  explicit BCPaintData(DrawTarget& aDrawTarget) : mDrawTarget(aDrawTarget) {}
+
+  DrawTarget& mDrawTarget;
+};
+
+struct BCCreateWebRenderCommandsData {
+  BCCreateWebRenderCommandsData(wr::DisplayListBuilder& aBuilder,
+                                const layers::StackingContextHelper& aSc,
+                                const nsPoint& aOffsetToReferenceFrame)
+      : mBuilder(aBuilder),
+        mSc(aSc),
+        mOffsetToReferenceFrame(aOffsetToReferenceFrame) {}
+
+  wr::DisplayListBuilder& mBuilder;
+  const layers::StackingContextHelper& mSc;
+  const nsPoint& mOffsetToReferenceFrame;
+};
+
+struct BCPaintBorderAction {
+  explicit BCPaintBorderAction(DrawTarget& aDrawTarget)
+      : mMode(Mode::Paint), mPaintData(aDrawTarget) {}
+
+  BCPaintBorderAction(wr::DisplayListBuilder& aBuilder,
+                      const layers::StackingContextHelper& aSc,
+                      const nsPoint& aOffsetToReferenceFrame)
+      : mMode(Mode::CreateWebRenderCommands),
+        mCreateWebRenderCommandsData(aBuilder, aSc, aOffsetToReferenceFrame) {}
+
+  ~BCPaintBorderAction() {
+    // mCreateWebRenderCommandsData is in a union which means the destructor
+    // wouldn't be called when BCPaintBorderAction get destroyed. So call the
+    // destructor here explicitly.
+    if (mMode == Mode::CreateWebRenderCommands) {
+      mCreateWebRenderCommandsData.~BCCreateWebRenderCommandsData();
+    }
+  }
+
+  enum class Mode {
+    Paint,
+    CreateWebRenderCommands,
+  };
+
+  Mode mMode;
+
+  union {
+    BCPaintData mPaintData;
+    BCCreateWebRenderCommandsData mCreateWebRenderCommandsData;
+  };
+};
+
+// Iterates over borders (iStart border, corner, bStart border) in the cell map
+// within a damage area from iStart to iEnd, bStart to bEnd. All members are in
+// terms of the 1st in flow frames, except where suffixed by InFlow.
+class BCPaintBorderIterator {
+ public:
+  explicit BCPaintBorderIterator(nsTableFrame* aTable);
+  void Reset();
+
+  /**
+   * Determine the damage area in terms of rows and columns and finalize
+   * mInitialOffsetI and mInitialOffsetB.
+   * @param aDirtyRect - dirty rect in table coordinates
+   * @return - true if we need to paint something given dirty rect
+   */
+  bool SetDamageArea(const nsRect& aDamageRect);
+  void First();
+  void Next();
+  void AccumulateOrDoActionInlineDirSegment(BCPaintBorderAction& aAction);
+  void AccumulateOrDoActionBlockDirSegment(BCPaintBorderAction& aAction);
+  void ResetVerInfo();
+  void StoreColumnWidth(int32_t aIndex);
+  bool BlockDirSegmentOwnsCorner();
+
+  nsTableFrame* mTable;
+  nsTableFrame* mTableFirstInFlow;
+  nsTableCellMap* mTableCellMap;
+  nsCellMap* mCellMap;
+  WritingMode mTableWM;
+  nsTableFrame::RowGroupArray mRowGroups;
+
+  nsTableRowGroupFrame* mPrevRg;
+  nsTableRowGroupFrame* mRg;
+  bool mIsRepeatedHeader;
+  bool mIsRepeatedFooter;
+  nsTableRowGroupFrame* mStartRg;   // first row group in the damagearea
+  int32_t mRgIndex;                 // current row group index in the
+                                    // mRowgroups array
+  int32_t mFifRgFirstRowIndex;      // start row index of the first in
+                                    // flow of the row group
+  int32_t mRgFirstRowIndex;         // row index of the first row in the
+                                    // row group
+  int32_t mRgLastRowIndex;          // row index of the last row in the row
+                                    // group
+  int32_t mNumTableRows;            // number of rows in the table and all
+                                    // continuations
+  int32_t mNumTableCols;            // number of columns in the table
+  int32_t mColIndex;                // with respect to the table
+  int32_t mRowIndex;                // with respect to the table
+  int32_t mRepeatedHeaderRowIndex;  // row index in a repeated
+                                    // header, it's equivalent to
+                                    // mRowIndex when we're in a repeated
+                                    // header, and set to the last row
+                                    // index of a repeated header when
+                                    // we're not
+  bool mIsNewRow;
+  bool mAtEnd;  // the iterator cycled over all
+                // borders
+  nsTableRowFrame* mPrevRow;
+  nsTableRowFrame* mRow;
+  nsTableRowFrame* mStartRow;  // first row in a inside the damagearea
+
+  // cell properties
+  nsTableCellFrame* mPrevCell;
+  nsTableCellFrame* mCell;
+  BCCellData* mPrevCellData;
+  BCCellData* mCellData;
+  BCData* mBCData;
+
+  bool IsTableBStartMost() {
+    return (mRowIndex == 0) && !mTable->GetPrevInFlow();
+  }
+  bool IsTableIEndMost() { return (mColIndex >= mNumTableCols); }
+  bool IsTableBEndMost() {
+    return (mRowIndex >= mNumTableRows) && !mTable->GetNextInFlow();
+  }
+  bool IsTableIStartMost() { return (mColIndex == 0); }
+  bool IsDamageAreaBStartMost() const {
+    return mRowIndex == mDamageArea.StartRow();
+  }
+  bool IsDamageAreaIEndMost() const {
+    return mColIndex >= mDamageArea.EndCol();
+  }
+  bool IsDamageAreaBEndMost() const {
+    return mRowIndex >= mDamageArea.EndRow();
+  }
+  bool IsDamageAreaIStartMost() const {
+    return mColIndex == mDamageArea.StartCol();
+  }
+  int32_t GetRelativeColIndex() const {
+    return mColIndex - mDamageArea.StartCol();
+  }
+
+  TableArea mDamageArea;  // damageArea in cellmap coordinates
+  bool IsAfterRepeatedHeader() {
+    return !mIsRepeatedHeader && (mRowIndex == (mRepeatedHeaderRowIndex + 1));
+  }
+  bool StartRepeatedFooter() const {
+    return mIsRepeatedFooter && mRowIndex == mRgFirstRowIndex &&
+           mRowIndex != mDamageArea.StartRow();
+  }
+
+  nscoord mInitialOffsetI;  // offsetI of the first border with
+                            // respect to the table
+  nscoord mInitialOffsetB;  // offsetB of the first border with
+                            // respect to the table
+  nscoord mNextOffsetB;     // offsetB of the next segment
+  // this array is used differently when
+  // inline-dir and block-dir borders are drawn
+  // When inline-dir border are drawn we cache
+  // the column widths and the width of the
+  // block-dir borders that arrive from bStart
+  // When we draw block-dir borders we store
+  // lengths and width for block-dir borders
+  // before they are drawn while we  move over
+  // the columns in the damage area
+  // It has one more elements than columns are
+  // in the table.
+  UniquePtr<BCBlockDirSeg[]> mBlockDirInfo;
+  BCInlineDirSeg mInlineSeg;        // the inline-dir segment while we
+                                    // move over the colums
+  BCPixelSize mPrevInlineSegBSize;  // the bSize of the previous
+                                    // inline-dir border
+
+ private:
+  bool SetNewRow(nsTableRowFrame* aRow = nullptr);
+  bool SetNewRowGroup();
+  void SetNewData(int32_t aRowIndex, int32_t aColIndex);
+};
+
+BCPaintBorderIterator::BCPaintBorderIterator(nsTableFrame* aTable)
+    : mTable(aTable),
+      mTableFirstInFlow(static_cast<nsTableFrame*>(aTable->FirstInFlow())),
+      mTableCellMap(aTable->GetCellMap()),
+      mCellMap(nullptr),
+      mTableWM(aTable->Style()),
+      mRowGroups(aTable->OrderedRowGroups()),
+      mPrevRg(nullptr),
+      mRg(nullptr),
+      mIsRepeatedHeader(false),
+      mIsRepeatedFooter(false),
+      mStartRg(nullptr),
+      mRgIndex(0),
+      mFifRgFirstRowIndex(0),
+      mRgFirstRowIndex(0),
+      mRgLastRowIndex(0),
+      mColIndex(0),
+      mRowIndex(0),
+      mIsNewRow(false),
+      mAtEnd(false),
+      mPrevRow(nullptr),
+      mRow(nullptr),
+      mStartRow(nullptr),
+      mPrevCell(nullptr),
+      mCell(nullptr),
+      mPrevCellData(nullptr),
+      mCellData(nullptr),
+      mBCData(nullptr),
+      mInitialOffsetI(0),
+      mNextOffsetB(0),
+      mPrevInlineSegBSize(0) {
+  MOZ_ASSERT(mTable->IsBorderCollapse(),
+             "Why are we here if the table is not border-collapsed?");
+
+  const LogicalMargin bp = mTable->GetIncludedOuterBCBorder(mTableWM);
+  // block position of first row in damage area
+  mInitialOffsetB = mTable->GetPrevInFlow() ? 0 : bp.BStart(mTableWM);
+  mNumTableRows = mTable->GetRowCount();
+  mNumTableCols = mTable->GetColCount();
+
+  // initialize to a non existing index
+  mRepeatedHeaderRowIndex = -99;
+}
+
+bool BCPaintBorderIterator::SetDamageArea(const nsRect& aDirtyRect) {
+  nsSize containerSize = mTable->GetSize();
+  LogicalRect dirtyRect(mTableWM, aDirtyRect, containerSize);
+  uint32_t startRowIndex, endRowIndex, startColIndex, endColIndex;
+  startRowIndex = endRowIndex = startColIndex = endColIndex = 0;
+  bool done = false;
+  bool haveIntersect = false;
+  // find startRowIndex, endRowIndex
+  nscoord rowB = mInitialOffsetB;
+  nsPresContext* presContext = mTable->PresContext();
+  for (uint32_t rgIdx = 0; rgIdx < mRowGroups.Length() && !done; rgIdx++) {
+    nsTableRowGroupFrame* rgFrame = mRowGroups[rgIdx];
+    for (nsTableRowFrame* rowFrame = rgFrame->GetFirstRow(); rowFrame;
+         rowFrame = rowFrame->GetNextRow()) {
+      // get the row rect relative to the table rather than the row group
+      nscoord rowBSize = rowFrame->BSize(mTableWM);
+      if (haveIntersect) {
+        // conservatively estimate the half border widths outside the row
+        nscoord borderHalf = mTable->GetPrevInFlow()
+                                 ? 0
+                                 : presContext->DevPixelsToAppUnits(
+                                       rowFrame->GetBStartBCBorderWidth() + 1);
+
+        if (dirtyRect.BEnd(mTableWM) >= rowB - borderHalf) {
+          nsTableRowFrame* fifRow =
+              static_cast<nsTableRowFrame*>(rowFrame->FirstInFlow());
+          endRowIndex = fifRow->GetRowIndex();
+        } else
+          done = true;
+      } else {
+        // conservatively estimate the half border widths outside the row
+        nscoord borderHalf = mTable->GetNextInFlow()
+                                 ? 0
+                                 : presContext->DevPixelsToAppUnits(
+                                       rowFrame->GetBEndBCBorderWidth() + 1);
+        if (rowB + rowBSize + borderHalf >= dirtyRect.BStart(mTableWM)) {
+          mStartRg = rgFrame;
+          mStartRow = rowFrame;
+          nsTableRowFrame* fifRow =
+              static_cast<nsTableRowFrame*>(rowFrame->FirstInFlow());
+          startRowIndex = endRowIndex = fifRow->GetRowIndex();
+          haveIntersect = true;
+        } else {
+          mInitialOffsetB += rowBSize;
+        }
+      }
+      rowB += rowBSize;
+    }
+  }
+  mNextOffsetB = mInitialOffsetB;
+
+  // XXX comment refers to the obsolete NS_FRAME_OUTSIDE_CHILDREN flag
+  // XXX but I don't understand it, so not changing it for now
+  // table wrapper borders overflow the table, so the table might be
+  // target to other areas as the NS_FRAME_OUTSIDE_CHILDREN is set
+  // on the table
+  if (!haveIntersect) return false;
+  // find startColIndex, endColIndex, startColX
+  haveIntersect = false;
+  if (0 == mNumTableCols) return false;
+
+  LogicalMargin bp = mTable->GetIncludedOuterBCBorder(mTableWM);
+
+  // inline position of first col in damage area
+  mInitialOffsetI = bp.IStart(mTableWM);
+
+  nscoord x = 0;
+  int32_t colIdx;
+  for (colIdx = 0; colIdx != mNumTableCols; colIdx++) {
+    nsTableColFrame* colFrame = mTableFirstInFlow->GetColFrame(colIdx);
+    if (!colFrame) ABORT1(false);
+    // get the col rect relative to the table rather than the col group
+    nscoord colISize = colFrame->ISize(mTableWM);
+    if (haveIntersect) {
+      // conservatively estimate the iStart half border width outside the col
+      nscoord iStartBorderHalf = presContext->DevPixelsToAppUnits(
+          colFrame->GetIStartBorderWidth() + 1);
+      if (dirtyRect.IEnd(mTableWM) >= x - iStartBorderHalf) {
+        endColIndex = colIdx;
+      } else
+        break;
+    } else {
+      // conservatively estimate the iEnd half border width outside the col
+      nscoord iEndBorderHalf =
+          presContext->DevPixelsToAppUnits(colFrame->GetIEndBorderWidth() + 1);
+      if (x + colISize + iEndBorderHalf >= dirtyRect.IStart(mTableWM)) {
+        startColIndex = endColIndex = colIdx;
+        haveIntersect = true;
+      } else {
+        mInitialOffsetI += colISize;
+      }
+    }
+    x += colISize;
+  }
+  if (!haveIntersect) return false;
+  mDamageArea =
+      TableArea(startColIndex, startRowIndex,
+                1 + DeprecatedAbs<int32_t>(endColIndex - startColIndex),
+                1 + endRowIndex - startRowIndex);
+
+  Reset();
+  mBlockDirInfo = MakeUnique<BCBlockDirSeg[]>(mDamageArea.ColCount() + 1);
+  return true;
+}
+
+void BCPaintBorderIterator::Reset() {
+  mAtEnd = true;  // gets reset when First() is called
+  mRg = mStartRg;
+  mPrevRow = nullptr;
+  mRow = mStartRow;
+  mRowIndex = 0;
+  mColIndex = 0;
+  mRgIndex = -1;
+  mPrevCell = nullptr;
+  mCell = nullptr;
+  mPrevCellData = nullptr;
+  mCellData = nullptr;
+  mBCData = nullptr;
+  ResetVerInfo();
+}
+
+/**
+ * Set the iterator data to a new cellmap coordinate
+ * @param aRowIndex - the row index
+ * @param aColIndex - the col index
+ */
+void BCPaintBorderIterator::SetNewData(int32_t aY, int32_t aX) {
+  if (!mTableCellMap || !mTableCellMap->mBCInfo) ABORT0();
+
+  mColIndex = aX;
+  mRowIndex = aY;
+  mPrevCellData = mCellData;
+  if (IsTableIEndMost() && IsTableBEndMost()) {
+    mCell = nullptr;
+    mBCData = &mTableCellMap->mBCInfo->mBEndIEndCorner;
+  } else if (IsTableIEndMost()) {
+    mCellData = nullptr;
+    mBCData = &mTableCellMap->mBCInfo->mIEndBorders.ElementAt(aY);
+  } else if (IsTableBEndMost()) {
+    mCellData = nullptr;
+    mBCData = &mTableCellMap->mBCInfo->mBEndBorders.ElementAt(aX);
+  } else {
+    // We should have set mCellMap during SetNewRowGroup, but if we failed to
+    // find the appropriate map there, let's just give up.
+    // Bailing out here may leave us with some missing borders, but seems
+    // preferable to crashing. (Bug 1442018)
+    if (MOZ_UNLIKELY(!mCellMap)) {
+      ABORT0();
+    }
+    if (uint32_t(mRowIndex - mFifRgFirstRowIndex) < mCellMap->mRows.Length()) {
+      mBCData = nullptr;
+      mCellData = (BCCellData*)mCellMap->mRows[mRowIndex - mFifRgFirstRowIndex]
+                      .SafeElementAt(mColIndex);
+      if (mCellData) {
+        mBCData = &mCellData->mData;
+        if (!mCellData->IsOrig()) {
+          if (mCellData->IsRowSpan()) {
+            aY -= mCellData->GetRowSpanOffset();
+          }
+          if (mCellData->IsColSpan()) {
+            aX -= mCellData->GetColSpanOffset();
+          }
+          if ((aX >= 0) && (aY >= 0)) {
+            mCellData =
+                (BCCellData*)mCellMap->mRows[aY - mFifRgFirstRowIndex][aX];
+          }
+        }
+        if (mCellData->IsOrig()) {
+          mPrevCell = mCell;
+          mCell = mCellData->GetCellFrame();
+        }
+      }
+    }
+  }
+}
+
+/**
+ * Set the iterator to a new row
+ * @param aRow - the new row frame, if null the iterator will advance to the
+ *               next row
+ */
+bool BCPaintBorderIterator::SetNewRow(nsTableRowFrame* aRow) {
+  mPrevRow = mRow;
+  mRow = (aRow) ? aRow : mRow->GetNextRow();
+  if (mRow) {
+    mIsNewRow = true;
+    mRowIndex = mRow->GetRowIndex();
+    mColIndex = mDamageArea.StartCol();
+    mPrevInlineSegBSize = 0;
+    if (mIsRepeatedHeader) {
+      mRepeatedHeaderRowIndex = mRowIndex;
+    }
+  } else {
+    mAtEnd = true;
+  }
+  return !mAtEnd;
+}
+
+/**
+ * Advance the iterator to the next row group
+ */
+bool BCPaintBorderIterator::SetNewRowGroup() {
+  mRgIndex++;
+
+  mIsRepeatedHeader = false;
+  mIsRepeatedFooter = false;
+
+  NS_ASSERTION(mRgIndex >= 0, "mRgIndex out of bounds");
+  if (uint32_t(mRgIndex) < mRowGroups.Length()) {
+    mPrevRg = mRg;
+    mRg = mRowGroups[mRgIndex];
+    nsTableRowGroupFrame* fifRg =
+        static_cast<nsTableRowGroupFrame*>(mRg->FirstInFlow());
+    mFifRgFirstRowIndex = fifRg->GetStartRowIndex();
+    mRgFirstRowIndex = mRg->GetStartRowIndex();
+    mRgLastRowIndex = mRgFirstRowIndex + mRg->GetRowCount() - 1;
+
+    if (SetNewRow(mRg->GetFirstRow())) {
+      mCellMap = mTableCellMap->GetMapFor(fifRg, nullptr);
+      if (!mCellMap) ABORT1(false);
+    }
+    if (mTable->GetPrevInFlow() && !mRg->GetPrevInFlow()) {
+      // if mRowGroup doesn't have a prev in flow, then it may be a repeated
+      // header or footer
+      const nsStyleDisplay* display = mRg->StyleDisplay();
+      if (mRowIndex == mDamageArea.StartRow()) {
+        mIsRepeatedHeader =
+            (mozilla::StyleDisplay::TableHeaderGroup == display->mDisplay);
+      } else {
+        mIsRepeatedFooter =
+            (mozilla::StyleDisplay::TableFooterGroup == display->mDisplay);
+      }
+    }
+  } else {
+    mAtEnd = true;
+  }
+  return !mAtEnd;
+}
+
+/**
+ *  Move the iterator to the first position in the damageArea
+ */
+void BCPaintBorderIterator::First() {
+  if (!mTable || mDamageArea.StartCol() >= mNumTableCols ||
+      mDamageArea.StartRow() >= mNumTableRows)
+    ABORT0();
+
+  mAtEnd = false;
+
+  uint32_t numRowGroups = mRowGroups.Length();
+  for (uint32_t rgY = 0; rgY < numRowGroups; rgY++) {
+    nsTableRowGroupFrame* rowG = mRowGroups[rgY];
+    int32_t start = rowG->GetStartRowIndex();
+    int32_t end = start + rowG->GetRowCount() - 1;
+    if (mDamageArea.StartRow() >= start && mDamageArea.StartRow() <= end) {
+      mRgIndex = rgY - 1;  // SetNewRowGroup increments rowGroupIndex
+      if (SetNewRowGroup()) {
+        while (mRowIndex < mDamageArea.StartRow() && !mAtEnd) {
+          SetNewRow();
+        }
+        if (!mAtEnd) {
+          SetNewData(mDamageArea.StartRow(), mDamageArea.StartCol());
+        }
+      }
+      return;
+    }
+  }
+  mAtEnd = true;
+}
+
+/**
+ * Advance the iterator to the next position
+ */
+void BCPaintBorderIterator::Next() {
+  if (mAtEnd) ABORT0();
+  mIsNewRow = false;
+
+  mColIndex++;
+  if (mColIndex > mDamageArea.EndCol()) {
+    mRowIndex++;
+    if (mRowIndex == mDamageArea.EndRow()) {
+      mColIndex = mDamageArea.StartCol();
+    } else if (mRowIndex < mDamageArea.EndRow()) {
+      if (mRowIndex <= mRgLastRowIndex) {
+        SetNewRow();
+      } else {
+        SetNewRowGroup();
+      }
+    } else {
+      mAtEnd = true;
+    }
+  }
+  if (!mAtEnd) {
+    SetNewData(mRowIndex, mColIndex);
+  }
+}
+
+// XXX if CalcVerCornerOffset and CalcHorCornerOffset remain similar, combine
+// them
+// XXX Update terminology from physical to logical
+/** Compute the vertical offset of a vertical border segment
+ * @param aCornerOwnerSide - which side owns the corner
+ * @param aCornerSubWidth  - how wide is the nonwinning side of the corner
+ * @param aHorWidth        - how wide is the horizontal edge of the corner
+ * @param aIsStartOfSeg    - does this corner start a new segment
+ * @param aIsBevel         - is this corner beveled
+ * @return                 - offset in twips
+ */
+static nscoord CalcVerCornerOffset(nsPresContext* aPresContext,
+                                   LogicalSide aCornerOwnerSide,
+                                   BCPixelSize aCornerSubWidth,
+                                   BCPixelSize aHorWidth, bool aIsStartOfSeg,
+                                   bool aIsBevel) {
+  nscoord offset = 0;
+  // XXX These should be replaced with appropriate side-specific macros (which?)
+  BCPixelSize smallHalf, largeHalf;
+  if (IsBlock(aCornerOwnerSide)) {
+    DivideBCBorderSize(aCornerSubWidth, smallHalf, largeHalf);
+    if (aIsBevel) {
+      offset = (aIsStartOfSeg) ? -largeHalf : smallHalf;
+    } else {
+      offset =
+          (eLogicalSideBStart == aCornerOwnerSide) ? smallHalf : -largeHalf;
+    }
+  } else {
+    DivideBCBorderSize(aHorWidth, smallHalf, largeHalf);
+    if (aIsBevel) {
+      offset = (aIsStartOfSeg) ? -largeHalf : smallHalf;
+    } else {
+      offset = (aIsStartOfSeg) ? smallHalf : -largeHalf;
+    }
+  }
+  return aPresContext->DevPixelsToAppUnits(offset);
+}
+
+/** Compute the horizontal offset of a horizontal border segment
+ * @param aCornerOwnerSide - which side owns the corner
+ * @param aCornerSubWidth  - how wide is the nonwinning side of the corner
+ * @param aVerWidth        - how wide is the vertical edge of the corner
+ * @param aIsStartOfSeg    - does this corner start a new segment
+ * @param aIsBevel         - is this corner beveled
+ * @return                 - offset in twips
+ */
+static nscoord CalcHorCornerOffset(nsPresContext* aPresContext,
+                                   LogicalSide aCornerOwnerSide,
+                                   BCPixelSize aCornerSubWidth,
+                                   BCPixelSize aVerWidth, bool aIsStartOfSeg,
+                                   bool aIsBevel) {
+  nscoord offset = 0;
+  // XXX These should be replaced with appropriate side-specific macros (which?)
+  BCPixelSize smallHalf, largeHalf;
+  if (IsInline(aCornerOwnerSide)) {
+    DivideBCBorderSize(aCornerSubWidth, smallHalf, largeHalf);
+    if (aIsBevel) {
+      offset = (aIsStartOfSeg) ? -largeHalf : smallHalf;
+    } else {
+      offset =
+          (eLogicalSideIStart == aCornerOwnerSide) ? smallHalf : -largeHalf;
+    }
+  } else {
+    DivideBCBorderSize(aVerWidth, smallHalf, largeHalf);
+    if (aIsBevel) {
+      offset = (aIsStartOfSeg) ? -largeHalf : smallHalf;
+    } else {
+      offset = (aIsStartOfSeg) ? smallHalf : -largeHalf;
+    }
+  }
+  return aPresContext->DevPixelsToAppUnits(offset);
+}
+
+BCBlockDirSeg::BCBlockDirSeg()
+    : mFirstRowGroup(nullptr),
+      mFirstRow(nullptr),
+      mBEndInlineSegBSize(0),
+      mBEndOffset(0),
+      mIsBEndBevel(false) {
+  mCol = nullptr;
+  mFirstCell = mLastCell = mAjaCell = nullptr;
+  mOffsetI = mOffsetB = mLength = mWidth = mBStartBevelOffset = 0;
+  mBStartBevelSide = eLogicalSideBStart;
+  mOwner = eCellOwner;
+}
+
+/**
+ * Start a new block-direction segment
+ * @param aIter         - iterator containing the structural information
+ * @param aBorderOwner  - determines the border style
+ * @param aBlockSegISize  - the width of segment in pixel
+ * @param aInlineSegBSize - the width of the inline-dir segment joining the
+ * corner at the start
+ */
+void BCBlockDirSeg::Start(BCPaintBorderIterator& aIter,
+                          BCBorderOwner aBorderOwner,
+                          BCPixelSize aBlockSegISize,
+                          BCPixelSize aInlineSegBSize,
+                          Maybe<nscoord> aEmptyRowEndBSize) {
+  LogicalSide ownerSide = eLogicalSideBStart;
+  bool bevel = false;
+
+  nscoord cornerSubWidth =
+      (aIter.mBCData) ? aIter.mBCData->GetCorner(ownerSide, bevel) : 0;
+
+  bool bStartBevel = (aBlockSegISize > 0) ? bevel : false;
+  BCPixelSize maxInlineSegBSize =
+      std::max(aIter.mPrevInlineSegBSize, aInlineSegBSize);
+  nsPresContext* presContext = aIter.mTable->PresContext();
+  nscoord offset = CalcVerCornerOffset(presContext, ownerSide, cornerSubWidth,
+                                       maxInlineSegBSize, true, bStartBevel);
+
+  mBStartBevelOffset =
+      bStartBevel ? presContext->DevPixelsToAppUnits(maxInlineSegBSize) : 0;
+  // XXX this assumes that only corners where 2 segments join can be beveled
+  mBStartBevelSide =
+      (aInlineSegBSize > 0) ? eLogicalSideIEnd : eLogicalSideIStart;
+  if (aEmptyRowEndBSize && *aEmptyRowEndBSize < offset) {
+    // This segment is starting from an empty row. This will require the the
+    // starting segment to overlap with the previously drawn segment, unless the
+    // empty row's size clears the overlap.
+    mOffsetB += *aEmptyRowEndBSize;
+  } else {
+    mOffsetB += offset;
+  }
+  mLength = -offset;
+  mWidth = aBlockSegISize;
+  mOwner = aBorderOwner;
+  mFirstCell = aIter.mCell;
+  mFirstRowGroup = aIter.mRg;
+  mFirstRow = aIter.mRow;
+  if (aIter.GetRelativeColIndex() > 0) {
+    mAjaCell = aIter.mBlockDirInfo[aIter.GetRelativeColIndex() - 1].mLastCell;
+  }
+}
+
+/**
+ * Initialize the block-dir segments with information that will persist for any
+ * block-dir segment in this column
+ * @param aIter - iterator containing the structural information
+ */
+void BCBlockDirSeg::Initialize(BCPaintBorderIterator& aIter) {
+  int32_t relColIndex = aIter.GetRelativeColIndex();
+  mCol = aIter.IsTableIEndMost()
+             ? aIter.mBlockDirInfo[relColIndex - 1].mCol
+             : aIter.mTableFirstInFlow->GetColFrame(aIter.mColIndex);
+  if (!mCol) ABORT0();
+  if (0 == relColIndex) {
+    mOffsetI = aIter.mInitialOffsetI;
+  }
+  // set mOffsetI for the next column
+  if (!aIter.IsDamageAreaIEndMost()) {
+    aIter.mBlockDirInfo[relColIndex + 1].mOffsetI =
+        mOffsetI + mCol->ISize(aIter.mTableWM);
+  }
+  mOffsetB = aIter.mInitialOffsetB;
+  mLastCell = aIter.mCell;
+}
+
+/**
+ * Compute the offsets for the bEnd corner of a block-dir segment
+ * @param aIter           - iterator containing the structural information
+ * @param aInlineSegBSize - the width of the inline-dir segment joining the
+ * corner at the start
+ */
+void BCBlockDirSeg::GetBEndCorner(BCPaintBorderIterator& aIter,
+                                  BCPixelSize aInlineSegBSize) {
+  LogicalSide ownerSide = eLogicalSideBStart;
+  nscoord cornerSubWidth = 0;
+  bool bevel = false;
+  if (aIter.mBCData) {
+    cornerSubWidth = aIter.mBCData->GetCorner(ownerSide, bevel);
+  }
+  mIsBEndBevel = (mWidth > 0) ? bevel : false;
+  mBEndInlineSegBSize = std::max(aIter.mPrevInlineSegBSize, aInlineSegBSize);
+  mBEndOffset = CalcVerCornerOffset(aIter.mTable->PresContext(), ownerSide,
+                                    cornerSubWidth, mBEndInlineSegBSize, false,
+                                    mIsBEndBevel);
+  mLength += mBEndOffset;
+}
+
+Maybe<BCBorderParameters> BCBlockDirSeg::BuildBorderParameters(
+    BCPaintBorderIterator& aIter, BCPixelSize aInlineSegBSize) {
+  BCBorderParameters result;
+
+  // get the border style, color and paint the segment
+  LogicalSide side =
+      aIter.IsDamageAreaIEndMost() ? eLogicalSideIEnd : eLogicalSideIStart;
+  int32_t relColIndex = aIter.GetRelativeColIndex();
+  nsTableColFrame* col = mCol;
+  if (!col) ABORT1(Nothing());
+  nsTableCellFrame* cell = mFirstCell;  // ???
+  nsIFrame* owner = nullptr;
+  result.mBorderStyle = StyleBorderStyle::Solid;
+  result.mBorderColor = 0xFFFFFFFF;
+  result.mBackfaceIsVisible = true;
+
+  // All the tables frames have the same presContext, so we just use any one
+  // that exists here:
+  nsPresContext* presContext = aIter.mTable->PresContext();
+  result.mAppUnitsPerDevPixel = presContext->AppUnitsPerDevPixel();
+
+  switch (mOwner) {
+    case eTableOwner:
+      owner = aIter.mTable;
+      break;
+    case eAjaColGroupOwner:
+      side = eLogicalSideIEnd;
+      if (!aIter.IsTableIEndMost() && (relColIndex > 0)) {
+        col = aIter.mBlockDirInfo[relColIndex - 1].mCol;
+      }
+      [[fallthrough]];
+    case eColGroupOwner:
+      if (col) {
+        owner = col->GetParent();
+      }
+      break;
+    case eAjaColOwner:
+      side = eLogicalSideIEnd;
+      if (!aIter.IsTableIEndMost() && (relColIndex > 0)) {
+        col = aIter.mBlockDirInfo[relColIndex - 1].mCol;
+      }
+      [[fallthrough]];
+    case eColOwner:
+      owner = col;
+      break;
+    case eAjaRowGroupOwner:
+      NS_ERROR("a neighboring rowgroup can never own a vertical border");
+      [[fallthrough]];
+    case eRowGroupOwner:
+      NS_ASSERTION(aIter.IsTableIStartMost() || aIter.IsTableIEndMost(),
+                   "row group can own border only at table edge");
+      owner = mFirstRowGroup;
+      break;
+    case eAjaRowOwner:
+      NS_ERROR("program error");
+      [[fallthrough]];
+    case eRowOwner:
+      NS_ASSERTION(aIter.IsTableIStartMost() || aIter.IsTableIEndMost(),
+                   "row can own border only at table edge");
+      owner = mFirstRow;
+      break;
+    case eAjaCellOwner:
+      side = eLogicalSideIEnd;
+      cell = mAjaCell;
+      [[fallthrough]];
+    case eCellOwner:
+      owner = cell;
+      break;
+  }
+  if (owner) {
+    ::GetPaintStyleInfo(owner, aIter.mTableWM, side, &result.mBorderStyle,
+                        &result.mBorderColor);
+    result.mBackfaceIsVisible = !owner->BackfaceIsHidden();
+  }
+  BCPixelSize smallHalf, largeHalf;
+  DivideBCBorderSize(mWidth, smallHalf, largeHalf);
+  LogicalRect segRect(
+      aIter.mTableWM, mOffsetI - presContext->DevPixelsToAppUnits(largeHalf),
+      mOffsetB, presContext->DevPixelsToAppUnits(mWidth), mLength);
+  nscoord bEndBevelOffset =
+      (mIsBEndBevel) ? presContext->DevPixelsToAppUnits(mBEndInlineSegBSize)
+                     : 0;
+  LogicalSide bEndBevelSide =
+      (aInlineSegBSize > 0) ? eLogicalSideIEnd : eLogicalSideIStart;
+
+  // Convert logical to physical sides/coordinates for DrawTableBorderSegment.
+
+  result.mBorderRect =
+      segRect.GetPhysicalRect(aIter.mTableWM, aIter.mTable->GetSize());
+  // XXX For reversed vertical writing-modes (with direction:rtl), we need to
+  // invert physicalRect's y-position here, with respect to the table.
+  // However, it's not worth fixing the border positions here until the
+  // ordering of the table columns themselves is also fixed (bug 1180528).
+
+  result.mStartBevelSide = aIter.mTableWM.PhysicalSide(mBStartBevelSide);
+  result.mEndBevelSide = aIter.mTableWM.PhysicalSide(bEndBevelSide);
+  result.mStartBevelOffset = mBStartBevelOffset;
+  result.mEndBevelOffset = bEndBevelOffset;
+  // In vertical-rl mode, the 'start' and 'end' of the block-dir (horizontal)
+  // border segment need to be swapped because DrawTableBorderSegment will
+  // apply the 'start' bevel at the left edge, and 'end' at the right.
+  // (Note: In this case, startBevelSide/endBevelSide will usually both be
+  // "top" or "bottom". DrawTableBorderSegment works purely with physical
+  // coordinates, so it expects startBevelOffset to be the indentation-from-
+  // the-left for the "start" (left) end of the border-segment, and
+  // endBevelOffset is the indentation-from-the-right for the "end" (right)
+  // end of the border-segment. We've got them reversed, since our block dir
+  // is RTL, so we have to swap them here.)
+  if (aIter.mTableWM.IsVerticalRL()) {
+    std::swap(result.mStartBevelSide, result.mEndBevelSide);
+    std::swap(result.mStartBevelOffset, result.mEndBevelOffset);
+  }
+
+  return Some(result);
+}
+
+/**
+ * Paint the block-dir segment
+ * @param aIter           - iterator containing the structural information
+ * @param aDrawTarget     - the draw target
+ * @param aInlineSegBSize - the width of the inline-dir segment joining the
+ *                          corner at the start
+ */
+void BCBlockDirSeg::Paint(BCPaintBorderIterator& aIter, DrawTarget& aDrawTarget,
+                          BCPixelSize aInlineSegBSize) {
+  Maybe<BCBorderParameters> param =
+      BuildBorderParameters(aIter, aInlineSegBSize);
+  if (param.isNothing()) {
+    return;
+  }
+
+  nsCSSRendering::DrawTableBorderSegment(
+      aDrawTarget, param->mBorderStyle, param->mBorderColor, param->mBorderRect,
+      param->mAppUnitsPerDevPixel, param->mStartBevelSide,
+      param->mStartBevelOffset, param->mEndBevelSide, param->mEndBevelOffset);
+}
+
+// Pushes a border bevel triangle and substracts the relevant rectangle from
+// aRect, which, after all the bevels, will end up being a solid segment rect.
+static void AdjustAndPushBevel(wr::DisplayListBuilder& aBuilder,
+                               wr::LayoutRect& aRect, nscolor aColor,
+                               const nsCSSRendering::Bevel& aBevel,
+                               int32_t aAppUnitsPerDevPixel,
+                               bool aBackfaceIsVisible, bool aIsStart) {
+  if (!aBevel.mOffset) {
+    return;
+  }
+
+  const auto kTransparent = wr::ToColorF(gfx::DeviceColor(0., 0., 0., 0.));
+  const bool horizontal =
+      aBevel.mSide == eSideTop || aBevel.mSide == eSideBottom;
+
+  // Crappy CSS triangle as known by every web developer ever :)
+  Float offset = NSAppUnitsToFloatPixels(aBevel.mOffset, aAppUnitsPerDevPixel);
+  wr::LayoutRect bevelRect = aRect;
+  wr::BorderSide bevelBorder[4];
+  for (const auto i : mozilla::AllPhysicalSides()) {
+    bevelBorder[i] =
+        wr::ToBorderSide(ToDeviceColor(aColor), StyleBorderStyle::Solid);
+  }
+
+  // We're creating a half-transparent triangle using the border primitive.
+  //
+  // Classic web-dev trick, with a gotcha: we use a single corner to avoid
+  // seams and rounding errors.
+  //
+  // Classic web-dev trick :P
+  auto borderWidths = wr::ToBorderWidths(0, 0, 0, 0);
+  bevelBorder[aBevel.mSide].color = kTransparent;
+  if (aIsStart) {
+    if (horizontal) {
+      bevelBorder[eSideLeft].color = kTransparent;
+      borderWidths.left = offset;
+    } else {
+      bevelBorder[eSideTop].color = kTransparent;
+      borderWidths.top = offset;
+    }
+  } else {
+    if (horizontal) {
+      bevelBorder[eSideRight].color = kTransparent;
+      borderWidths.right = offset;
+    } else {
+      bevelBorder[eSideBottom].color = kTransparent;
+      borderWidths.bottom = offset;
+    }
+  }
+
+  if (horizontal) {
+    if (aIsStart) {
+      aRect.min.x += offset;
+      aRect.max.x += offset;
+    } else {
+      bevelRect.min.x += aRect.width() - offset;
+      bevelRect.max.x += aRect.width() - offset;
+    }
+    aRect.max.x -= offset;
+    bevelRect.max.y = bevelRect.min.y + aRect.height();
+    bevelRect.max.x = bevelRect.min.x + offset;
+    if (aBevel.mSide == eSideTop) {
+      borderWidths.bottom = aRect.height();
+    } else {
+      borderWidths.top = aRect.height();
+    }
+  } else {
+    if (aIsStart) {
+      aRect.min.y += offset;
+      aRect.max.y += offset;
+    } else {
+      bevelRect.min.y += aRect.height() - offset;
+      bevelRect.max.y += aRect.height() - offset;
+    }
+    aRect.max.y -= offset;
+    bevelRect.max.x = bevelRect.min.x + aRect.width();
+    bevelRect.max.y = bevelRect.min.y + offset;
+    if (aBevel.mSide == eSideLeft) {
+      borderWidths.right = aRect.width();
+    } else {
+      borderWidths.left = aRect.width();
+    }
+  }
+
+  Range<const wr::BorderSide> wrsides(bevelBorder, 4);
+  // It's important to _not_ anti-alias the bevel, because otherwise we wouldn't
+  // be able bevel to sides of the same color without bleeding in the middle.
+  aBuilder.PushBorder(bevelRect, bevelRect, aBackfaceIsVisible, borderWidths,
+                      wrsides, wr::EmptyBorderRadius(),
+                      wr::AntialiasBorder::No);
+}
+
+static void CreateWRCommandsForBeveledBorder(
+    const BCBorderParameters& aBorderParams, wr::DisplayListBuilder& aBuilder,
+    const layers::StackingContextHelper& aSc, const nsPoint& aOffset) {
+  MOZ_ASSERT(aBorderParams.NeedToBevel());
+
+  AutoTArray<nsCSSRendering::SolidBeveledBorderSegment, 3> segments;
+  nsCSSRendering::GetTableBorderSolidSegments(
+      segments, aBorderParams.mBorderStyle, aBorderParams.mBorderColor,
+      aBorderParams.mBorderRect, aBorderParams.mAppUnitsPerDevPixel,
+      aBorderParams.mStartBevelSide, aBorderParams.mStartBevelOffset,
+      aBorderParams.mEndBevelSide, aBorderParams.mEndBevelOffset);
+
+  for (const auto& segment : segments) {
+    auto rect = LayoutDeviceRect::FromUnknownRect(NSRectToRect(
+        segment.mRect + aOffset, aBorderParams.mAppUnitsPerDevPixel));
+    auto r = wr::ToLayoutRect(rect);
+    auto color = wr::ToColorF(ToDeviceColor(segment.mColor));
+
+    // Adjust for the start bevel if needed.
+    AdjustAndPushBevel(aBuilder, r, segment.mColor, segment.mStartBevel,
+                       aBorderParams.mAppUnitsPerDevPixel,
+                       aBorderParams.mBackfaceIsVisible, true);
+
+    AdjustAndPushBevel(aBuilder, r, segment.mColor, segment.mEndBevel,
+                       aBorderParams.mAppUnitsPerDevPixel,
+                       aBorderParams.mBackfaceIsVisible, false);
+
+    aBuilder.PushRect(r, r, aBorderParams.mBackfaceIsVisible, false, false,
+                      color);
+  }
+}
+
+static void CreateWRCommandsForBorderSegment(
+    const BCBorderParameters& aBorderParams, wr::DisplayListBuilder& aBuilder,
+    const layers::StackingContextHelper& aSc, const nsPoint& aOffset) {
+  if (aBorderParams.NeedToBevel()) {
+    CreateWRCommandsForBeveledBorder(aBorderParams, aBuilder, aSc, aOffset);
+    return;
+  }
+
+  auto borderRect = LayoutDeviceRect::FromUnknownRect(NSRectToRect(
+      aBorderParams.mBorderRect + aOffset, aBorderParams.mAppUnitsPerDevPixel));
+
+  wr::LayoutRect r = wr::ToLayoutRect(borderRect);
+  wr::BorderSide wrSide[4];
+  for (const auto i : mozilla::AllPhysicalSides()) {
+    wrSide[i] = wr::ToBorderSide(ToDeviceColor(aBorderParams.mBorderColor),
+                                 StyleBorderStyle::None);
+  }
+  const bool horizontal = aBorderParams.mStartBevelSide == eSideTop ||
+                          aBorderParams.mStartBevelSide == eSideBottom;
+  auto borderWidth = horizontal ? r.height() : r.width();
+
+  // All border style is set to none except left side. So setting the widths of
+  // each side to width of rect is fine.
+  auto borderWidths = wr::ToBorderWidths(0, 0, 0, 0);
+
+  wrSide[horizontal ? eSideTop : eSideLeft] = wr::ToBorderSide(
+      ToDeviceColor(aBorderParams.mBorderColor), aBorderParams.mBorderStyle);
+
+  if (horizontal) {
+    borderWidths.top = borderWidth;
+  } else {
+    borderWidths.left = borderWidth;
+  }
+
+  Range<const wr::BorderSide> wrsides(wrSide, 4);
+  aBuilder.PushBorder(r, r, aBorderParams.mBackfaceIsVisible, borderWidths,
+                      wrsides, wr::EmptyBorderRadius());
+}
+
+void BCBlockDirSeg::CreateWebRenderCommands(
+    BCPaintBorderIterator& aIter, BCPixelSize aInlineSegBSize,
+    wr::DisplayListBuilder& aBuilder, const layers::StackingContextHelper& aSc,
+    const nsPoint& aOffset) {
+  Maybe<BCBorderParameters> param =
+      BuildBorderParameters(aIter, aInlineSegBSize);
+  if (param.isNothing()) {
+    return;
+  }
+
+  CreateWRCommandsForBorderSegment(*param, aBuilder, aSc, aOffset);
+}
+
+/**
+ * Advance the start point of a segment
+ */
+void BCBlockDirSeg::AdvanceOffsetB() { mOffsetB += mLength - mBEndOffset; }
+
+/**
+ * Accumulate the current segment
+ */
+void BCBlockDirSeg::IncludeCurrentBorder(BCPaintBorderIterator& aIter) {
+  mLastCell = aIter.mCell;
+  mLength += aIter.mRow->BSize(aIter.mTableWM);
+}
+
+BCInlineDirSeg::BCInlineDirSeg()
+    : mIsIEndBevel(false),
+      mIEndBevelOffset(0),
+      mIEndBevelSide(eLogicalSideBStart),
+      mEndOffset(0),
+      mOwner(eTableOwner) {
+  mOffsetI = mOffsetB = mLength = mWidth = mIStartBevelOffset = 0;
+  mIStartBevelSide = eLogicalSideBStart;
+  mFirstCell = mAjaCell = nullptr;
+}
+
+/** Initialize an inline-dir border segment for painting
+  * @param aIter              - iterator storing the current and adjacent frames
+  * @param aBorderOwner       - which frame owns the border
+  * @param aBEndBlockSegISize - block-dir segment width coming from up
+  * @param aInlineSegBSize    - the thickness of the segment
+  +  */
+void BCInlineDirSeg::Start(BCPaintBorderIterator& aIter,
+                           BCBorderOwner aBorderOwner,
+                           BCPixelSize aBEndBlockSegISize,
+                           BCPixelSize aInlineSegBSize) {
+  LogicalSide cornerOwnerSide = eLogicalSideBStart;
+  bool bevel = false;
+
+  mOwner = aBorderOwner;
+  nscoord cornerSubWidth =
+      (aIter.mBCData) ? aIter.mBCData->GetCorner(cornerOwnerSide, bevel) : 0;
+
+  bool iStartBevel = (aInlineSegBSize > 0) ? bevel : false;
+  int32_t relColIndex = aIter.GetRelativeColIndex();
+  nscoord maxBlockSegISize =
+      std::max(aIter.mBlockDirInfo[relColIndex].mWidth, aBEndBlockSegISize);
+  nscoord offset =
+      CalcHorCornerOffset(aIter.mTable->PresContext(), cornerOwnerSide,
+                          cornerSubWidth, maxBlockSegISize, true, iStartBevel);
+  mIStartBevelOffset =
+      (iStartBevel && (aInlineSegBSize > 0)) ? maxBlockSegISize : 0;
+  // XXX this assumes that only corners where 2 segments join can be beveled
+  mIStartBevelSide =
+      (aBEndBlockSegISize > 0) ? eLogicalSideBEnd : eLogicalSideBStart;
+  mOffsetI += offset;
+  mLength = -offset;
+  mWidth = aInlineSegBSize;
+  mFirstCell = aIter.mCell;
+  mAjaCell = (aIter.IsDamageAreaBStartMost())
+                 ? nullptr
+                 : aIter.mBlockDirInfo[relColIndex].mLastCell;
+}
+
+/**
+ * Compute the offsets for the iEnd corner of an inline-dir segment
+ * @param aIter         - iterator containing the structural information
+ * @param aIStartSegISize - the iSize of the block-dir segment joining the
+ * corner at the start
+ */
+void BCInlineDirSeg::GetIEndCorner(BCPaintBorderIterator& aIter,
+                                   BCPixelSize aIStartSegISize) {
+  LogicalSide ownerSide = eLogicalSideBStart;
+  nscoord cornerSubWidth = 0;
+  bool bevel = false;
+  if (aIter.mBCData) {
+    cornerSubWidth = aIter.mBCData->GetCorner(ownerSide, bevel);
+  }
+
+  mIsIEndBevel = (mWidth > 0) ? bevel : 0;
+  int32_t relColIndex = aIter.GetRelativeColIndex();
+  nscoord verWidth =
+      std::max(aIter.mBlockDirInfo[relColIndex].mWidth, aIStartSegISize);
+  nsPresContext* presContext = aIter.mTable->PresContext();
+  mEndOffset = CalcHorCornerOffset(presContext, ownerSide, cornerSubWidth,
+                                   verWidth, false, mIsIEndBevel);
+  mLength += mEndOffset;
+  mIEndBevelOffset =
+      (mIsIEndBevel) ? presContext->DevPixelsToAppUnits(verWidth) : 0;
+  mIEndBevelSide =
+      (aIStartSegISize > 0) ? eLogicalSideBEnd : eLogicalSideBStart;
+}
+
+Maybe<BCBorderParameters> BCInlineDirSeg::BuildBorderParameters(
+    BCPaintBorderIterator& aIter) {
+  BCBorderParameters result;
+
+  // get the border style, color and paint the segment
+  LogicalSide side =
+      aIter.IsDamageAreaBEndMost() ? eLogicalSideBEnd : eLogicalSideBStart;
+  nsIFrame* rg = aIter.mRg;
+  if (!rg) ABORT1(Nothing());
+  nsIFrame* row = aIter.mRow;
+  if (!row) ABORT1(Nothing());
+  nsIFrame* cell = mFirstCell;
+  nsIFrame* col;
+  nsIFrame* owner = nullptr;
+  result.mBackfaceIsVisible = true;
+
+  // All the tables frames have the same presContext, so we just use any one
+  // that exists here:
+  nsPresContext* presContext = aIter.mTable->PresContext();
+  result.mAppUnitsPerDevPixel = presContext->AppUnitsPerDevPixel();
+
+  result.mBorderStyle = StyleBorderStyle::Solid;
+  result.mBorderColor = 0xFFFFFFFF;
+
+  switch (mOwner) {
+    case eTableOwner:
+      owner = aIter.mTable;
+      break;
+    case eAjaColGroupOwner:
+      NS_ERROR("neighboring colgroups can never own an inline-dir border");
+      [[fallthrough]];
+    case eColGroupOwner:
+      NS_ASSERTION(aIter.IsTableBStartMost() || aIter.IsTableBEndMost(),
+                   "col group can own border only at the table edge");
+      col = aIter.mTableFirstInFlow->GetColFrame(aIter.mColIndex - 1);
+      if (!col) ABORT1(Nothing());
+      owner = col->GetParent();
+      break;
+    case eAjaColOwner:
+      NS_ERROR("neighboring column can never own an inline-dir border");
+      [[fallthrough]];
+    case eColOwner:
+      NS_ASSERTION(aIter.IsTableBStartMost() || aIter.IsTableBEndMost(),
+                   "col can own border only at the table edge");
+      owner = aIter.mTableFirstInFlow->GetColFrame(aIter.mColIndex - 1);
+      break;
+    case eAjaRowGroupOwner:
+      side = eLogicalSideBEnd;
+      rg = (aIter.IsTableBEndMost()) ? aIter.mRg : aIter.mPrevRg;
+      [[fallthrough]];
+    case eRowGroupOwner:
+      owner = rg;
+      break;
+    case eAjaRowOwner:
+      side = eLogicalSideBEnd;
+      row = (aIter.IsTableBEndMost()) ? aIter.mRow : aIter.mPrevRow;
+      [[fallthrough]];
+    case eRowOwner:
+      owner = row;
+      break;
+    case eAjaCellOwner:
+      side = eLogicalSideBEnd;
+      // if this is null due to the damage area origin-y > 0, then the border
+      // won't show up anyway
+      cell = mAjaCell;
+      [[fallthrough]];
+    case eCellOwner:
+      owner = cell;
+      break;
+  }
+  if (owner) {
+    ::GetPaintStyleInfo(owner, aIter.mTableWM, side, &result.mBorderStyle,
+                        &result.mBorderColor);
+    result.mBackfaceIsVisible = !owner->BackfaceIsHidden();
+  }
+  BCPixelSize smallHalf, largeHalf;
+  DivideBCBorderSize(mWidth, smallHalf, largeHalf);
+  LogicalRect segRect(aIter.mTableWM, mOffsetI,
+                      mOffsetB - presContext->DevPixelsToAppUnits(largeHalf),
+                      mLength, presContext->DevPixelsToAppUnits(mWidth));
+
+  // Convert logical to physical sides/coordinates for DrawTableBorderSegment.
+  result.mBorderRect =
+      segRect.GetPhysicalRect(aIter.mTableWM, aIter.mTable->GetSize());
+  result.mStartBevelSide = aIter.mTableWM.PhysicalSide(mIStartBevelSide);
+  result.mEndBevelSide = aIter.mTableWM.PhysicalSide(mIEndBevelSide);
+  result.mStartBevelOffset =
+      presContext->DevPixelsToAppUnits(mIStartBevelOffset);
+  result.mEndBevelOffset = mIEndBevelOffset;
+  // With inline-RTL directionality, the 'start' and 'end' of the inline-dir
+  // border segment need to be swapped because DrawTableBorderSegment will
+  // apply the 'start' bevel physically at the left or top edge, and 'end' at
+  // the right or bottom.
+  // (Note: startBevelSide/endBevelSide will be "top" or "bottom" in horizontal
+  // writing mode, or "left" or "right" in vertical mode.
+  // DrawTableBorderSegment works purely with physical coordinates, so it
+  // expects startBevelOffset to be the indentation-from-the-left or top end
+  // of the border-segment, and endBevelOffset is the indentation-from-the-
+  // right or bottom end. If the writing mode is inline-RTL, our "start" and
+  // "end" will be reversed from this physical-coord view, so we have to swap
+  // them here.
+  if (aIter.mTableWM.IsBidiRTL()) {
+    std::swap(result.mStartBevelSide, result.mEndBevelSide);
+    std::swap(result.mStartBevelOffset, result.mEndBevelOffset);
+  }
+
+  return Some(result);
+}
+
+/**
+ * Paint the inline-dir segment
+ * @param aIter       - iterator containing the structural information
+ * @param aDrawTarget - the draw target
+ */
+void BCInlineDirSeg::Paint(BCPaintBorderIterator& aIter,
+                           DrawTarget& aDrawTarget) {
+  Maybe<BCBorderParameters> param = BuildBorderParameters(aIter);
+  if (param.isNothing()) {
+    return;
+  }
+
+  nsCSSRendering::DrawTableBorderSegment(
+      aDrawTarget, param->mBorderStyle, param->mBorderColor, param->mBorderRect,
+      param->mAppUnitsPerDevPixel, param->mStartBevelSide,
+      param->mStartBevelOffset, param->mEndBevelSide, param->mEndBevelOffset);
+}
+
+void BCInlineDirSeg::CreateWebRenderCommands(
+    BCPaintBorderIterator& aIter, wr::DisplayListBuilder& aBuilder,
+    const layers::StackingContextHelper& aSc, const nsPoint& aPt) {
+  Maybe<BCBorderParameters> param = BuildBorderParameters(aIter);
+  if (param.isNothing()) {
+    return;
+  }
+
+  CreateWRCommandsForBorderSegment(*param, aBuilder, aSc, aPt);
+}
+
+/**
+ * Advance the start point of a segment
+ */
+void BCInlineDirSeg::AdvanceOffsetI() { mOffsetI += (mLength - mEndOffset); }
+
+/**
+ * Accumulate the current segment
+ */
+void BCInlineDirSeg::IncludeCurrentBorder(BCPaintBorderIterator& aIter) {
+  mLength += aIter.mBlockDirInfo[aIter.GetRelativeColIndex()].mColWidth;
+}
+
+/**
+ * store the column width information while painting inline-dir segment
+ */
+void BCPaintBorderIterator::StoreColumnWidth(int32_t aIndex) {
+  if (IsTableIEndMost()) {
+    mBlockDirInfo[aIndex].mColWidth = mBlockDirInfo[aIndex - 1].mColWidth;
+  } else {
+    nsTableColFrame* col = mTableFirstInFlow->GetColFrame(mColIndex);
+    if (!col) ABORT0();
+    mBlockDirInfo[aIndex].mColWidth = col->ISize(mTableWM);
+  }
+}
+/**
+ * Determine if a block-dir segment owns the corner
+ */
+bool BCPaintBorderIterator::BlockDirSegmentOwnsCorner() {
+  LogicalSide cornerOwnerSide = eLogicalSideBStart;
+  bool bevel = false;
+  if (mBCData) {
+    mBCData->GetCorner(cornerOwnerSide, bevel);
+  }
+  // unitialized ownerside, bevel
+  return (eLogicalSideBStart == cornerOwnerSide) ||
+         (eLogicalSideBEnd == cornerOwnerSide);
+}
+
+/**
+ * Paint if necessary an inline-dir segment, otherwise accumulate it
+ * @param aDrawTarget - the draw target
+ */
+void BCPaintBorderIterator::AccumulateOrDoActionInlineDirSegment(
+    BCPaintBorderAction& aAction) {
+  int32_t relColIndex = GetRelativeColIndex();
+  // store the current col width if it hasn't been already
+  if (mBlockDirInfo[relColIndex].mColWidth < 0) {
+    StoreColumnWidth(relColIndex);
+  }
+
+  BCBorderOwner borderOwner = eCellOwner;
+  BCBorderOwner ignoreBorderOwner;
+  bool isSegStart = true;
+  bool ignoreSegStart;
+
+  nscoord iStartSegISize =
+      mBCData ? mBCData->GetIStartEdge(ignoreBorderOwner, ignoreSegStart) : 0;
+  nscoord bStartSegBSize =
+      mBCData ? mBCData->GetBStartEdge(borderOwner, isSegStart) : 0;
+
+  if (mIsNewRow || (IsDamageAreaIStartMost() && IsDamageAreaBEndMost())) {
+    // reset for every new row and on the bottom of the last row
+    mInlineSeg.mOffsetB = mNextOffsetB;
+    mNextOffsetB = mNextOffsetB + mRow->BSize(mTableWM);
+    mInlineSeg.mOffsetI = mInitialOffsetI;
+    mInlineSeg.Start(*this, borderOwner, iStartSegISize, bStartSegBSize);
+  }
+
+  if (!IsDamageAreaIStartMost() &&
+      (isSegStart || IsDamageAreaIEndMost() || BlockDirSegmentOwnsCorner())) {
+    // paint the previous seg or the current one if IsDamageAreaIEndMost()
+    if (mInlineSeg.mLength > 0) {
+      mInlineSeg.GetIEndCorner(*this, iStartSegISize);
+      if (mInlineSeg.mWidth > 0) {
+        if (aAction.mMode == BCPaintBorderAction::Mode::Paint) {
+          mInlineSeg.Paint(*this, aAction.mPaintData.mDrawTarget);
+        } else {
+          MOZ_ASSERT(aAction.mMode ==
+                     BCPaintBorderAction::Mode::CreateWebRenderCommands);
+          mInlineSeg.CreateWebRenderCommands(
+              *this, aAction.mCreateWebRenderCommandsData.mBuilder,
+              aAction.mCreateWebRenderCommandsData.mSc,
+              aAction.mCreateWebRenderCommandsData.mOffsetToReferenceFrame);
+        }
+      }
+      mInlineSeg.AdvanceOffsetI();
+    }
+    mInlineSeg.Start(*this, borderOwner, iStartSegISize, bStartSegBSize);
+  }
+  mInlineSeg.IncludeCurrentBorder(*this);
+  mBlockDirInfo[relColIndex].mWidth = iStartSegISize;
+  mBlockDirInfo[relColIndex].mLastCell = mCell;
+}
+
+/**
+ * Paint if necessary a block-dir segment, otherwise accumulate it
+ * @param aDrawTarget - the draw target
+ */
+void BCPaintBorderIterator::AccumulateOrDoActionBlockDirSegment(
+    BCPaintBorderAction& aAction) {
+  BCBorderOwner borderOwner = eCellOwner;
+  BCBorderOwner ignoreBorderOwner;
+  bool isSegStart = true;
+  bool ignoreSegStart;
+
+  nscoord blockSegISize =
+      mBCData ? mBCData->GetIStartEdge(borderOwner, isSegStart) : 0;
+  nscoord inlineSegBSize =
+      mBCData ? mBCData->GetBStartEdge(ignoreBorderOwner, ignoreSegStart) : 0;
+
+  int32_t relColIndex = GetRelativeColIndex();
+  BCBlockDirSeg& blockDirSeg = mBlockDirInfo[relColIndex];
+  if (!blockDirSeg.mCol) {  // on the first damaged row and the first segment in
+                            // the col
+    blockDirSeg.Initialize(*this);
+    blockDirSeg.Start(*this, borderOwner, blockSegISize, inlineSegBSize,
+                      Nothing{});
+  }
+
+  if (!IsDamageAreaBStartMost() &&
+      (isSegStart || IsDamageAreaBEndMost() || IsAfterRepeatedHeader() ||
+       StartRepeatedFooter())) {
+    Maybe<nscoord> emptyRowEndSize;
+    // paint the previous seg or the current one if IsDamageAreaBEndMost()
+    if (blockDirSeg.mLength > 0) {
+      blockDirSeg.GetBEndCorner(*this, inlineSegBSize);
+      if (blockDirSeg.mWidth > 0) {
+        if (aAction.mMode == BCPaintBorderAction::Mode::Paint) {
+          blockDirSeg.Paint(*this, aAction.mPaintData.mDrawTarget,
+                            inlineSegBSize);
+        } else {
+          MOZ_ASSERT(aAction.mMode ==
+                     BCPaintBorderAction::Mode::CreateWebRenderCommands);
+          blockDirSeg.CreateWebRenderCommands(
+              *this, inlineSegBSize,
+              aAction.mCreateWebRenderCommandsData.mBuilder,
+              aAction.mCreateWebRenderCommandsData.mSc,
+              aAction.mCreateWebRenderCommandsData.mOffsetToReferenceFrame);
+        }
+      }
+      blockDirSeg.AdvanceOffsetB();
+      if (mRow->PrincipalChildList().IsEmpty()) {
+        emptyRowEndSize = Some(mRow->BSize(mTableWM));
+      }
+    }
+    blockDirSeg.Start(*this, borderOwner, blockSegISize, inlineSegBSize,
+                      emptyRowEndSize);
+  }
+  blockDirSeg.IncludeCurrentBorder(*this);
+  mPrevInlineSegBSize = inlineSegBSize;
+}
+
+/**
+ * Reset the block-dir information cache
+ */
+void BCPaintBorderIterator::ResetVerInfo() {
+  if (mBlockDirInfo) {
+    memset(mBlockDirInfo.get(), 0,
+           mDamageArea.ColCount() * sizeof(BCBlockDirSeg));
+    // XXX reinitialize properly
+    for (auto xIndex : IntegerRange(mDamageArea.ColCount())) {
+      mBlockDirInfo[xIndex].mColWidth = -1;
+    }
+  }
+}
+
+void nsTableFrame::IterateBCBorders(BCPaintBorderAction& aAction,
+                                    const nsRect& aDirtyRect) {
+  // We first transfer the aDirtyRect into cellmap coordinates to compute which
+  // cell borders need to be painted
+  BCPaintBorderIterator iter(this);
+  if (!iter.SetDamageArea(aDirtyRect)) return;
+
+  // XXX comment still has physical terminology
+  // First, paint all of the vertical borders from top to bottom and left to
+  // right as they become complete. They are painted first, since they are less
+  // efficient to paint than horizontal segments. They were stored with as few
+  // segments as possible (since horizontal borders are painted last and
+  // possibly over them). For every cell in a row that fails in the damage are
+  // we look up if the current border would start a new segment, if so we paint
+  // the previously stored vertical segment and start a new segment. After
+  // this we  the now active segment with the current border. These
+  // segments are stored in mBlockDirInfo to be used on the next row
+  for (iter.First(); !iter.mAtEnd; iter.Next()) {
+    iter.AccumulateOrDoActionBlockDirSegment(aAction);
+  }
+
+  // Next, paint all of the inline-dir border segments from bStart to bEnd reuse
+  // the mBlockDirInfo array to keep track of col widths and block-dir segments
+  // for corner calculations
+  iter.Reset();
+  for (iter.First(); !iter.mAtEnd; iter.Next()) {
+    iter.AccumulateOrDoActionInlineDirSegment(aAction);
+  }
+}
+
+/**
+ * Method to paint BCBorders, this does not use currently display lists although
+ * it will do this in future
+ * @param aDrawTarget - the rendering context
+ * @param aDirtyRect  - inside this rectangle the BC Borders will redrawn
+ */
+void nsTableFrame::PaintBCBorders(DrawTarget& aDrawTarget,
+                                  const nsRect& aDirtyRect) {
+  BCPaintBorderAction action(aDrawTarget);
+  IterateBCBorders(action, aDirtyRect);
+}
+
+void nsTableFrame::CreateWebRenderCommandsForBCBorders(
+    wr::DisplayListBuilder& aBuilder,
+    const mozilla::layers::StackingContextHelper& aSc,
+    const nsRect& aVisibleRect, const nsPoint& aOffsetToReferenceFrame) {
+  BCPaintBorderAction action(aBuilder, aSc, aOffsetToReferenceFrame);
+  // We always draw whole table border for webrender. Passing the visible rect
+  // dirty rect.
+  IterateBCBorders(action, aVisibleRect - aOffsetToReferenceFrame);
+}
+
+bool nsTableFrame::RowHasSpanningCells(int32_t aRowIndex, int32_t aNumEffCols) {
+  bool result = false;
+  nsTableCellMap* cellMap = GetCellMap();
+  MOZ_ASSERT(cellMap, "bad call, cellMap not yet allocated.");
+  if (cellMap) {
+    result = cellMap->RowHasSpanningCells(aRowIndex, aNumEffCols);
+  }
+  return result;
+}
+
+bool nsTableFrame::RowIsSpannedInto(int32_t aRowIndex, int32_t aNumEffCols) {
+  bool result = false;
+  nsTableCellMap* cellMap = GetCellMap();
+  MOZ_ASSERT(cellMap, "bad call, cellMap not yet allocated.");
+  if (cellMap) {
+    result = cellMap->RowIsSpannedInto(aRowIndex, aNumEffCols);
+  }
+  return result;
+}
+
+/* static */
+void nsTableFrame::InvalidateTableFrame(nsIFrame* aFrame,
+                                        const nsRect& aOrigRect,
+                                        const nsRect& aOrigInkOverflow,
+                                        bool aIsFirstReflow) {
+  nsIFrame* parent = aFrame->GetParent();
+  NS_ASSERTION(parent, "What happened here?");
+
+  if (parent->HasAnyStateBits(NS_FRAME_FIRST_REFLOW)) {
+    // Don't bother; we'll invalidate the parent's overflow rect when
+    // we finish reflowing it.
+    return;
+  }
+
+  // The part that looks at both the rect and the overflow rect is a
+  // bit of a hack.  See nsBlockFrame::ReflowLine for an eloquent
+  // description of its hackishness.
+  //
+  // This doesn't really make sense now that we have DLBI.
+  // This code can probably be simplified a fair bit.
+  nsRect inkOverflow = aFrame->InkOverflowRect();
+  if (aIsFirstReflow || aOrigRect.TopLeft() != aFrame->GetPosition() ||
+      aOrigInkOverflow.TopLeft() != inkOverflow.TopLeft()) {
+    // Invalidate the old and new overflow rects.  Note that if the
+    // frame moved, we can't just use aOrigInkOverflow, since it's in
+    // coordinates relative to the old position.  So invalidate via
+    // aFrame's parent, and reposition that overflow rect to the right
+    // place.
+    // XXXbz this doesn't handle outlines, does it?
+    aFrame->InvalidateFrame();
+    parent->InvalidateFrameWithRect(aOrigInkOverflow + aOrigRect.TopLeft());
+  } else if (aOrigRect.Size() != aFrame->GetSize() ||
+             aOrigInkOverflow.Size() != inkOverflow.Size()) {
+    aFrame->InvalidateFrameWithRect(aOrigInkOverflow);
+    aFrame->InvalidateFrame();
+  }
+}
+
+void nsTableFrame::AppendDirectlyOwnedAnonBoxes(
+    nsTArray<OwnedAnonBox>& aResult) {
+  nsIFrame* wrapper = GetParent();
+  MOZ_ASSERT(wrapper->Style()->GetPseudoType() == PseudoStyleType::tableWrapper,
+             "What happened to our parent?");
+  aResult.AppendElement(
+      OwnedAnonBox(wrapper, &UpdateStyleOfOwnedAnonBoxesForTableWrapper));
+}
+
+/* static */
+void nsTableFrame::UpdateStyleOfOwnedAnonBoxesForTableWrapper(
+    nsIFrame* aOwningFrame, nsIFrame* aWrapperFrame,
+    ServoRestyleState& aRestyleState) {
+  MOZ_ASSERT(
+      aWrapperFrame->Style()->GetPseudoType() == PseudoStyleType::tableWrapper,
+      "What happened to our parent?");
+
+  RefPtr<ComputedStyle> newStyle =
+      aRestyleState.StyleSet().ResolveInheritingAnonymousBoxStyle(
+          PseudoStyleType::tableWrapper, aOwningFrame->Style());
+
+  // Figure out whether we have an actual change.  It's important that we do
+  // this, even though all the wrapper's changes are due to properties it
+  // inherits from us, because it's possible that no one ever asked us for those
+  // style structs and hence changes to them aren't reflected in
+  // the handled changes at all.
+  //
+  // Also note that extensions can add/remove stylesheets that change the styles
+  // of anonymous boxes directly, so we need to handle that potential change
+  // here.
+  //
+  // NOTE(emilio): We can't use the ChangesHandledFor optimization (and we
+  // assert against that), because the table wrapper is up in the frame tree
+  // compared to the owner frame.
+  uint32_t equalStructs;  // Not used, actually.
+  nsChangeHint wrapperHint =
+      aWrapperFrame->Style()->CalcStyleDifference(*newStyle, &equalStructs);
+
+  if (wrapperHint) {
+    aRestyleState.ChangeList().AppendChange(
+        aWrapperFrame, aWrapperFrame->GetContent(), wrapperHint);
+  }
+
+  for (nsIFrame* cur = aWrapperFrame; cur; cur = cur->GetNextContinuation()) {
+    cur->SetComputedStyle(newStyle);
+  }
+
+  MOZ_ASSERT(!aWrapperFrame->HasAnyStateBits(NS_FRAME_OWNS_ANON_BOXES),
+             "Wrapper frame doesn't have any anon boxes of its own!");
+}
+
+namespace mozilla {
+
+nsRect nsDisplayTableItem::GetBounds(nsDisplayListBuilder* aBuilder,
+                                     bool* aSnap) const {
+  *aSnap = false;
+  return mFrame->InkOverflowRectRelativeToSelf() + ToReferenceFrame();
+}
+
+nsDisplayTableBackgroundSet::nsDisplayTableBackgroundSet(
+    nsDisplayListBuilder* aBuilder, nsIFrame* aTable)
+    : mBuilder(aBuilder),
+      mColGroupBackgrounds(aBuilder),
+      mColBackgrounds(aBuilder),
+      mCurrentScrollParentId(aBuilder->GetCurrentScrollParentId()) {
+  mPrevTableBackgroundSet = mBuilder->SetTableBackgroundSet(this);
+  mozilla::DebugOnly<const nsIFrame*> reference =
+      mBuilder->FindReferenceFrameFor(aTable, &mToReferenceFrame);
+  MOZ_ASSERT(nsLayoutUtils::FindNearestCommonAncestorFrame(reference, aTable));
+  mDirtyRect = mBuilder->GetDirtyRect();
+  mCombinedTableClipChain =
+      mBuilder->ClipState().GetCurrentCombinedClipChain(aBuilder);
+  mTableASR = mBuilder->CurrentActiveScrolledRoot();
+}
+
+// A display item that draws all collapsed borders for a table.
+// At some point, we may want to find a nicer partitioning for dividing
+// border-collapse segments into their own display items.
+class nsDisplayTableBorderCollapse final : public nsDisplayTableItem {
+ public:
+  nsDisplayTableBorderCollapse(nsDisplayListBuilder* aBuilder,
+                               nsTableFrame* aFrame)
+      : nsDisplayTableItem(aBuilder, aFrame) {
+    MOZ_COUNT_CTOR(nsDisplayTableBorderCollapse);
+  }
+  MOZ_COUNTED_DTOR_OVERRIDE(nsDisplayTableBorderCollapse)
+
+  void Paint(nsDisplayListBuilder* aBuilder, gfxContext* aCtx) override;
+  bool CreateWebRenderCommands(
+      wr::DisplayListBuilder& aBuilder, wr::IpcResourceUpdateQueue& aResources,
+      const StackingContextHelper& aSc,
+      layers::RenderRootStateManager* aManager,
+      nsDisplayListBuilder* aDisplayListBuilder) override;
+  NS_DISPLAY_DECL_NAME("TableBorderCollapse", TYPE_TABLE_BORDER_COLLAPSE)
+};
+
+void nsDisplayTableBorderCollapse::Paint(nsDisplayListBuilder* aBuilder,
+                                         gfxContext* aCtx) {
+  nsPoint pt = ToReferenceFrame();
+  DrawTarget* drawTarget = aCtx->GetDrawTarget();
+
+  gfxPoint devPixelOffset = nsLayoutUtils::PointToGfxPoint(
+      pt, mFrame->PresContext()->AppUnitsPerDevPixel());
+
+  // XXX we should probably get rid of this translation at some stage
+  // But that would mean modifying PaintBCBorders, ugh
+  AutoRestoreTransform autoRestoreTransform(drawTarget);
+  drawTarget->SetTransform(
+      drawTarget->GetTransform().PreTranslate(ToPoint(devPixelOffset)));
+
+  static_cast<nsTableFrame*>(mFrame)->PaintBCBorders(
+      *drawTarget, GetPaintRect(aBuilder, aCtx) - pt);
+}
+
+bool nsDisplayTableBorderCollapse::CreateWebRenderCommands(
+    wr::DisplayListBuilder& aBuilder, wr::IpcResourceUpdateQueue& aResources,
+    const StackingContextHelper& aSc,
+    mozilla::layers::RenderRootStateManager* aManager,
+    nsDisplayListBuilder* aDisplayListBuilder) {
+  bool dummy;
+  static_cast<nsTableFrame*>(mFrame)->CreateWebRenderCommandsForBCBorders(
+      aBuilder, aSc, GetBounds(aDisplayListBuilder, &dummy),
+      ToReferenceFrame());
+  return true;
+}
+
+}  // namespace mozilla