4 files changed, 37 insertions, 36 deletions

diff --git a/layout/mathml/nsMathMLContainerFrame.cpp b/layout/mathml/nsMathMLContainerFrame.cpp
index b63792c288..fc334d1cae 100644
--- a/layout/mathml/nsMathMLContainerFrame.cpp
+++ b/layout/mathml/nsMathMLContainerFrame.cpp
@@ -829,39 +829,33 @@ static nscoord AddInterFrameSpacingToSize(ReflowOutput& aDesiredSize,
 
 /* virtual */
 void nsMathMLContainerFrame::MarkIntrinsicISizesDirty() {
-  mIntrinsicWidth = NS_INTRINSIC_ISIZE_UNKNOWN;
+  mIntrinsicISize = NS_INTRINSIC_ISIZE_UNKNOWN;
   nsContainerFrame::MarkIntrinsicISizesDirty();
 }
 
-void nsMathMLContainerFrame::UpdateIntrinsicWidth(
+void nsMathMLContainerFrame::UpdateIntrinsicISize(
     gfxContext* aRenderingContext) {
-  if (mIntrinsicWidth == NS_INTRINSIC_ISIZE_UNKNOWN) {
+  if (mIntrinsicISize == NS_INTRINSIC_ISIZE_UNKNOWN) {
     ReflowOutput desiredSize(GetWritingMode());
     GetIntrinsicISizeMetrics(aRenderingContext, desiredSize);
 
     // Include the additional width added by FixInterFrameSpacing to ensure
     // consistent width calculations.
     AddInterFrameSpacingToSize(desiredSize, this);
-    mIntrinsicWidth = desiredSize.ISize(GetWritingMode());
+    mIntrinsicISize = desiredSize.ISize(GetWritingMode());
   }
 }
 
 /* virtual */
 nscoord nsMathMLContainerFrame::GetMinISize(gfxContext* aRenderingContext) {
-  nscoord result;
-  DISPLAY_MIN_INLINE_SIZE(this, result);
-  UpdateIntrinsicWidth(aRenderingContext);
-  result = mIntrinsicWidth;
-  return result;
+  UpdateIntrinsicISize(aRenderingContext);
+  return mIntrinsicISize;
 }
 
 /* virtual */
 nscoord nsMathMLContainerFrame::GetPrefISize(gfxContext* aRenderingContext) {
-  nscoord result;
-  DISPLAY_PREF_INLINE_SIZE(this, result);
-  UpdateIntrinsicWidth(aRenderingContext);
-  result = mIntrinsicWidth;
-  return result;
+  UpdateIntrinsicISize(aRenderingContext);
+  return mIntrinsicISize;
 }
 
 /* virtual */
diff --git a/layout/mathml/nsMathMLContainerFrame.h b/layout/mathml/nsMathMLContainerFrame.h
index 805d7e03ca..24bc86c338 100644
--- a/layout/mathml/nsMathMLContainerFrame.h
+++ b/layout/mathml/nsMathMLContainerFrame.h
@@ -37,9 +37,7 @@ class nsMathMLContainerFrame : public nsContainerFrame, public nsMathMLFrame {
  public:
   nsMathMLContainerFrame(ComputedStyle* aStyle, nsPresContext* aPresContext,
                          ClassID aID)
-      : nsContainerFrame(aStyle, aPresContext, aID),
-        mIntrinsicWidth(NS_INTRINSIC_ISIZE_UNKNOWN),
-        mBlockStartAscent(0) {}
+      : nsContainerFrame(aStyle, aPresContext, aID) {}
 
   NS_DECL_QUERYFRAME_TARGET(nsMathMLContainerFrame)
   NS_DECL_QUERYFRAME
@@ -341,13 +339,13 @@ class nsMathMLContainerFrame : public nsContainerFrame, public nsMathMLFrame {
   static void DidReflowChildren(nsIFrame* aFirst, nsIFrame* aStop = nullptr);
 
   /**
-   * Recompute mIntrinsicWidth if it's not already up to date.
+   * Recompute mIntrinsicISize if it's not already up to date.
    */
-  void UpdateIntrinsicWidth(gfxContext* aRenderingContext);
+  void UpdateIntrinsicISize(gfxContext* aRenderingContext);
 
-  nscoord mIntrinsicWidth;
+  nscoord mIntrinsicISize = NS_INTRINSIC_ISIZE_UNKNOWN;
 
-  nscoord mBlockStartAscent;
+  nscoord mBlockStartAscent = 0;
 
  private:
   class RowChildFrameIterator;
@@ -429,8 +427,7 @@ class nsMathMLmathBlockFrame final : public nsBlockFrame {
  protected:
   explicit nsMathMLmathBlockFrame(ComputedStyle* aStyle,
                                   nsPresContext* aPresContext)
-      : nsBlockFrame(aStyle, aPresContext, kClassID) {
-  }
+      : nsBlockFrame(aStyle, aPresContext, kClassID) {}
   virtual ~nsMathMLmathBlockFrame() = default;
 };
 
diff --git a/layout/mathml/nsMathMLmoFrame.cpp b/layout/mathml/nsMathMLmoFrame.cpp
index e0d68234ae..e27709c0b0 100644
--- a/layout/mathml/nsMathMLmoFrame.cpp
+++ b/layout/mathml/nsMathMLmoFrame.cpp
@@ -8,6 +8,7 @@
 
 #include "gfxContext.h"
 #include "mozilla/PresShell.h"
+#include "mozilla/StaticPrefs_mathml.h"
 #include "nsCSSValue.h"
 #include "nsLayoutUtils.h"
 #include "nsPresContext.h"
@@ -145,15 +146,17 @@ void nsMathMLmoFrame::ProcessTextData() {
   mFlags |= allFlags & NS_MATHML_OPERATOR_ACCENT;
   mFlags |= allFlags & NS_MATHML_OPERATOR_MOVABLELIMITS;
 
-  // see if this is an operator that should be centered to cater for
-  // fonts that are not math-aware
-  if (1 == length) {
-    if ((ch == '+') || (ch == '=') || (ch == '*') ||
-        (ch == 0x2212) ||  // −
-        (ch == 0x2264) ||  // ≤
-        (ch == 0x2265) ||  // ≥
-        (ch == 0x00D7)) {  // ×
-      mFlags |= NS_MATHML_OPERATOR_CENTERED;
+  if (!StaticPrefs::mathml_centered_operators_disabled()) {
+    // see if this is an operator that should be centered to cater for
+    // fonts that are not math-aware
+    if (1 == length) {
+      if ((ch == '+') || (ch == '=') || (ch == '*') ||
+          (ch == 0x2212) ||  // −
+          (ch == 0x2264) ||  // ≤
+          (ch == 0x2265) ||  // ≥
+          (ch == 0x00D7)) {  // ×
+        mFlags |= NS_MATHML_OPERATOR_CENTERED;
+      }
     }
   }
 
@@ -593,9 +596,15 @@ nsMathMLmoFrame::Stretch(DrawTarget* aDrawTarget,
 
   // get the leading to be left at the top and the bottom of the stretched char
   // this seems more reliable than using fm->GetLeading() on suspicious fonts
-  nscoord em;
-  GetEmHeight(fm, em);
-  nscoord leading = NSToCoordRound(0.2f * em);
+  const nscoord leading = [&fm] {
+    if (StaticPrefs::
+            mathml_top_bottom_spacing_for_stretchy_operators_disabled()) {
+      return 0;
+    }
+    nscoord em;
+    GetEmHeight(fm, em);
+    return NSToCoordRound(0.2f * (float)em);
+  }();
 
   // Operators that are stretchy, or those that are to be centered
   // to cater for fonts that are not math-aware, are handled by the MathMLChar
diff --git a/layout/mathml/nsMathMLmtableFrame.h b/layout/mathml/nsMathMLmtableFrame.h
index 1a801de8fc..dee6c5ba7a 100644
--- a/layout/mathml/nsMathMLmtableFrame.h
+++ b/layout/mathml/nsMathMLmtableFrame.h
@@ -222,7 +222,8 @@ class nsMathMLmtdFrame final : public nsTableCellFrame {
                       mozilla::nsDisplayListBuilder* aBuilder,
                       const mozilla::nsDisplayListSet& aLists) override;
 
-  LogicalMargin GetBorderWidth(WritingMode aWM) const override;
+  mozilla::LogicalMargin GetBorderWidth(
+      mozilla::WritingMode aWM) const override;
 
   nsMargin GetBorderOverflow() override;