Adding upstream version 115.7.0esr.upstream/115.7.0esr

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

1 files changed, 1791 insertions, 0 deletions

diff --git a/gfx/thebes/gfxFontUtils.cpp b/gfx/thebes/gfxFontUtils.cpp
new file mode 100644
index 0000000000..02543607cd
--- /dev/null
+++ b/gfx/thebes/gfxFontUtils.cpp
@@ -0,0 +1,1791 @@
+/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* 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 "mozilla/ArrayUtils.h"
+#include "mozilla/BinarySearch.h"
+
+#include "gfxFontUtils.h"
+#include "gfxFontEntry.h"
+#include "gfxFontVariations.h"
+#include "gfxUtils.h"
+
+#include "nsServiceManagerUtils.h"
+
+#include "mozilla/Preferences.h"
+#include "mozilla/BinarySearch.h"
+#include "mozilla/Sprintf.h"
+#include "mozilla/Unused.h"
+
+#include "nsCOMPtr.h"
+#include "nsIUUIDGenerator.h"
+#include "mozilla/Encoding.h"
+
+#include "mozilla/ServoStyleSet.h"
+#include "mozilla/dom/WorkerCommon.h"
+
+#include "plbase64.h"
+#include "mozilla/Logging.h"
+
+#ifdef XP_MACOSX
+#  include <CoreFoundation/CoreFoundation.h>
+#endif
+
+#define LOG(log, args) MOZ_LOG(gfxPlatform::GetLog(log), LogLevel::Debug, args)
+
+#define UNICODE_BMP_LIMIT 0x10000
+
+using namespace mozilla;
+
+#pragma pack(1)
+
+typedef struct {
+  AutoSwap_PRUint16 format;
+  AutoSwap_PRUint16 reserved;
+  AutoSwap_PRUint32 length;
+  AutoSwap_PRUint32 language;
+  AutoSwap_PRUint32 startCharCode;
+  AutoSwap_PRUint32 numChars;
+} Format10CmapHeader;
+
+typedef struct {
+  AutoSwap_PRUint16 format;
+  AutoSwap_PRUint16 reserved;
+  AutoSwap_PRUint32 length;
+  AutoSwap_PRUint32 language;
+  AutoSwap_PRUint32 numGroups;
+} Format12CmapHeader;
+
+typedef struct {
+  AutoSwap_PRUint32 startCharCode;
+  AutoSwap_PRUint32 endCharCode;
+  AutoSwap_PRUint32 startGlyphId;
+} Format12Group;
+
+#pragma pack()
+
+void gfxSparseBitSet::Dump(const char* aPrefix, eGfxLog aWhichLog) const {
+  uint32_t numBlocks = mBlockIndex.Length();
+
+  for (uint32_t b = 0; b < numBlocks; b++) {
+    if (mBlockIndex[b] == NO_BLOCK) {
+      continue;
+    }
+    const Block* block = &mBlocks[mBlockIndex[b]];
+    const int BUFSIZE = 256;
+    char outStr[BUFSIZE];
+    int index = 0;
+    index += snprintf(&outStr[index], BUFSIZE - index, "%s u+%6.6x [", aPrefix,
+                      (b * BLOCK_SIZE_BITS));
+    for (int i = 0; i < 32; i += 4) {
+      for (int j = i; j < i + 4; j++) {
+        uint8_t bits = block->mBits[j];
+        uint8_t flip1 = ((bits & 0xaa) >> 1) | ((bits & 0x55) << 1);
+        uint8_t flip2 = ((flip1 & 0xcc) >> 2) | ((flip1 & 0x33) << 2);
+        uint8_t flipped = ((flip2 & 0xf0) >> 4) | ((flip2 & 0x0f) << 4);
+
+        index += snprintf(&outStr[index], BUFSIZE - index, "%2.2x", flipped);
+      }
+      if (i + 4 != 32) index += snprintf(&outStr[index], BUFSIZE - index, " ");
+    }
+    Unused << snprintf(&outStr[index], BUFSIZE - index, "]");
+    LOG(aWhichLog, ("%s", outStr));
+  }
+}
+
+nsresult gfxFontUtils::ReadCMAPTableFormat10(const uint8_t* aBuf,
+                                             uint32_t aLength,
+                                             gfxSparseBitSet& aCharacterMap) {
+  // Ensure table is large enough that we can safely read the header
+  NS_ENSURE_TRUE(aLength >= sizeof(Format10CmapHeader),
+                 NS_ERROR_GFX_CMAP_MALFORMED);
+
+  // Sanity-check header fields
+  const Format10CmapHeader* cmap10 =
+      reinterpret_cast<const Format10CmapHeader*>(aBuf);
+  NS_ENSURE_TRUE(uint16_t(cmap10->format) == 10, NS_ERROR_GFX_CMAP_MALFORMED);
+  NS_ENSURE_TRUE(uint16_t(cmap10->reserved) == 0, NS_ERROR_GFX_CMAP_MALFORMED);
+
+  uint32_t tablelen = cmap10->length;
+  NS_ENSURE_TRUE(tablelen >= sizeof(Format10CmapHeader) && tablelen <= aLength,
+                 NS_ERROR_GFX_CMAP_MALFORMED);
+
+  NS_ENSURE_TRUE(cmap10->language == 0, NS_ERROR_GFX_CMAP_MALFORMED);
+
+  uint32_t numChars = cmap10->numChars;
+  NS_ENSURE_TRUE(
+      tablelen == sizeof(Format10CmapHeader) + numChars * sizeof(uint16_t),
+      NS_ERROR_GFX_CMAP_MALFORMED);
+
+  uint32_t charCode = cmap10->startCharCode;
+  NS_ENSURE_TRUE(charCode <= CMAP_MAX_CODEPOINT &&
+                     charCode + numChars <= CMAP_MAX_CODEPOINT,
+                 NS_ERROR_GFX_CMAP_MALFORMED);
+
+  // glyphs[] array immediately follows the subtable header
+  const AutoSwap_PRUint16* glyphs =
+      reinterpret_cast<const AutoSwap_PRUint16*>(cmap10 + 1);
+
+  for (uint32_t i = 0; i < numChars; ++i) {
+    if (uint16_t(*glyphs) != 0) {
+      aCharacterMap.set(charCode);
+    }
+    ++charCode;
+    ++glyphs;
+  }
+
+  aCharacterMap.Compact();
+
+  return NS_OK;
+}
+
+nsresult gfxFontUtils::ReadCMAPTableFormat12or13(
+    const uint8_t* aBuf, uint32_t aLength, gfxSparseBitSet& aCharacterMap) {
+  // Format 13 has the same structure as format 12, the only difference is
+  // the interpretation of the glyphID field. So we can share the code here
+  // that reads the table and just records character coverage.
+
+  // Ensure table is large enough that we can safely read the header
+  NS_ENSURE_TRUE(aLength >= sizeof(Format12CmapHeader),
+                 NS_ERROR_GFX_CMAP_MALFORMED);
+
+  // Sanity-check header fields
+  const Format12CmapHeader* cmap12 =
+      reinterpret_cast<const Format12CmapHeader*>(aBuf);
+  NS_ENSURE_TRUE(
+      uint16_t(cmap12->format) == 12 || uint16_t(cmap12->format) == 13,
+      NS_ERROR_GFX_CMAP_MALFORMED);
+  NS_ENSURE_TRUE(uint16_t(cmap12->reserved) == 0, NS_ERROR_GFX_CMAP_MALFORMED);
+
+  uint32_t tablelen = cmap12->length;
+  NS_ENSURE_TRUE(tablelen >= sizeof(Format12CmapHeader) && tablelen <= aLength,
+                 NS_ERROR_GFX_CMAP_MALFORMED);
+
+  NS_ENSURE_TRUE(cmap12->language == 0, NS_ERROR_GFX_CMAP_MALFORMED);
+
+  // Check that the table is large enough for the group array
+  const uint32_t numGroups = cmap12->numGroups;
+  NS_ENSURE_TRUE(
+      (tablelen - sizeof(Format12CmapHeader)) / sizeof(Format12Group) >=
+          numGroups,
+      NS_ERROR_GFX_CMAP_MALFORMED);
+
+  // The array of groups immediately follows the subtable header.
+  const Format12Group* group =
+      reinterpret_cast<const Format12Group*>(aBuf + sizeof(Format12CmapHeader));
+
+  // Check that groups are in correct order and do not overlap,
+  // and record character coverage in aCharacterMap.
+  uint32_t prevEndCharCode = 0;
+  for (uint32_t i = 0; i < numGroups; i++, group++) {
+    uint32_t startCharCode = group->startCharCode;
+    const uint32_t endCharCode = group->endCharCode;
+    NS_ENSURE_TRUE((prevEndCharCode < startCharCode || i == 0) &&
+                       startCharCode <= endCharCode &&
+                       endCharCode <= CMAP_MAX_CODEPOINT,
+                   NS_ERROR_GFX_CMAP_MALFORMED);
+    // don't include a character that maps to glyph ID 0 (.notdef)
+    if (group->startGlyphId == 0) {
+      startCharCode++;
+    }
+    if (startCharCode <= endCharCode) {
+      aCharacterMap.SetRange(startCharCode, endCharCode);
+    }
+    prevEndCharCode = endCharCode;
+  }
+
+  aCharacterMap.Compact();
+
+  return NS_OK;
+}
+
+nsresult gfxFontUtils::ReadCMAPTableFormat4(const uint8_t* aBuf,
+                                            uint32_t aLength,
+                                            gfxSparseBitSet& aCharacterMap,
+                                            bool aIsSymbolFont) {
+  enum {
+    OffsetFormat = 0,
+    OffsetLength = 2,
+    OffsetLanguage = 4,
+    OffsetSegCountX2 = 6
+  };
+
+  NS_ENSURE_TRUE(ReadShortAt(aBuf, OffsetFormat) == 4,
+                 NS_ERROR_GFX_CMAP_MALFORMED);
+  uint16_t tablelen = ReadShortAt(aBuf, OffsetLength);
+  NS_ENSURE_TRUE(tablelen <= aLength, NS_ERROR_GFX_CMAP_MALFORMED);
+  NS_ENSURE_TRUE(tablelen > 16, NS_ERROR_GFX_CMAP_MALFORMED);
+
+  // This field should normally (except for Mac platform subtables) be zero
+  // according to the OT spec, but some buggy fonts have lang = 1 (which would
+  // be English for MacOS). E.g. Arial Narrow Bold, v. 1.1 (Tiger), Arial
+  // Unicode MS (see bug 530614). So accept either zero or one here; the error
+  // should be harmless.
+  NS_ENSURE_TRUE((ReadShortAt(aBuf, OffsetLanguage) & 0xfffe) == 0,
+                 NS_ERROR_GFX_CMAP_MALFORMED);
+
+  uint16_t segCountX2 = ReadShortAt(aBuf, OffsetSegCountX2);
+  NS_ENSURE_TRUE(tablelen >= 16 + (segCountX2 * 4),
+                 NS_ERROR_GFX_CMAP_MALFORMED);
+
+  const uint16_t segCount = segCountX2 / 2;
+
+  const uint16_t* endCounts = reinterpret_cast<const uint16_t*>(aBuf + 14);
+  const uint16_t* startCounts =
+      endCounts + 1 /* skip one uint16_t for reservedPad */ + segCount;
+  const uint16_t* idDeltas = startCounts + segCount;
+  const uint16_t* idRangeOffsets = idDeltas + segCount;
+  uint16_t prevEndCount = 0;
+  for (uint16_t i = 0; i < segCount; i++) {
+    const uint16_t endCount = ReadShortAt16(endCounts, i);
+    const uint16_t startCount = ReadShortAt16(startCounts, i);
+    const uint16_t idRangeOffset = ReadShortAt16(idRangeOffsets, i);
+
+    // sanity-check range
+    // This permits ranges to overlap by 1 character, which is strictly
+    // incorrect but occurs in Baskerville on OS X 10.7 (see bug 689087),
+    // and appears to be harmless in practice
+    NS_ENSURE_TRUE(startCount >= prevEndCount && startCount <= endCount,
+                   NS_ERROR_GFX_CMAP_MALFORMED);
+    prevEndCount = endCount;
+
+    if (idRangeOffset == 0) {
+      // figure out if there's a code in the range that would map to
+      // glyph ID 0 (.notdef); if so, we need to skip setting that
+      // character code in the map
+      const uint16_t skipCode = 65536 - ReadShortAt16(idDeltas, i);
+      if (startCount < skipCode) {
+        aCharacterMap.SetRange(startCount,
+                               std::min<uint16_t>(skipCode - 1, endCount));
+      }
+      if (skipCode < endCount) {
+        aCharacterMap.SetRange(std::max<uint16_t>(startCount, skipCode + 1),
+                               endCount);
+      }
+    } else {
+      // Unused: self-documenting.
+      // const uint16_t idDelta = ReadShortAt16(idDeltas, i);
+      for (uint32_t c = startCount; c <= endCount; ++c) {
+        if (c == 0xFFFF) break;
+
+        const uint16_t* gdata =
+            (idRangeOffset / 2 + (c - startCount) + &idRangeOffsets[i]);
+
+        NS_ENSURE_TRUE(
+            (uint8_t*)gdata > aBuf && (uint8_t*)gdata < aBuf + aLength,
+            NS_ERROR_GFX_CMAP_MALFORMED);
+
+        // make sure we have a glyph
+        if (*gdata != 0) {
+          // The glyph index at this point is:
+          uint16_t glyph = ReadShortAt16(idDeltas, i) + *gdata;
+          if (glyph) {
+            aCharacterMap.set(c);
+          }
+        }
+      }
+    }
+  }
+
+  if (aIsSymbolFont) {
+    // For fonts with "MS Symbol" encoding, we duplicate character mappings in
+    // the U+F0xx range down to U+00xx codepoints, so as to support fonts such
+    // as Wingdings.
+    // Note that if the font actually has cmap coverage for the U+00xx range
+    // (either duplicating the PUA codepoints or mapping to separate glyphs),
+    // this will not affect it.
+    for (uint32_t c = 0x0020; c <= 0x00ff; ++c) {
+      if (aCharacterMap.test(0xf000 + c)) {
+        aCharacterMap.set(c);
+      }
+    }
+  }
+
+  aCharacterMap.Compact();
+
+  return NS_OK;
+}
+
+nsresult gfxFontUtils::ReadCMAPTableFormat14(const uint8_t* aBuf,
+                                             uint32_t aLength,
+                                             const uint8_t*& aTable) {
+  enum {
+    OffsetFormat = 0,
+    OffsetTableLength = 2,
+    OffsetNumVarSelectorRecords = 6,
+    OffsetVarSelectorRecords = 10,
+
+    SizeOfVarSelectorRecord = 11,
+    VSRecOffsetVarSelector = 0,
+    VSRecOffsetDefUVSOffset = 3,
+    VSRecOffsetNonDefUVSOffset = 7,
+
+    SizeOfDefUVSTable = 4,
+    DefUVSOffsetStartUnicodeValue = 0,
+    DefUVSOffsetAdditionalCount = 3,
+
+    SizeOfNonDefUVSTable = 5,
+    NonDefUVSOffsetUnicodeValue = 0,
+    NonDefUVSOffsetGlyphID = 3
+  };
+  NS_ENSURE_TRUE(aLength >= OffsetVarSelectorRecords,
+                 NS_ERROR_GFX_CMAP_MALFORMED);
+
+  NS_ENSURE_TRUE(ReadShortAt(aBuf, OffsetFormat) == 14,
+                 NS_ERROR_GFX_CMAP_MALFORMED);
+
+  uint32_t tablelen = ReadLongAt(aBuf, OffsetTableLength);
+  NS_ENSURE_TRUE(tablelen <= aLength, NS_ERROR_GFX_CMAP_MALFORMED);
+  NS_ENSURE_TRUE(tablelen >= OffsetVarSelectorRecords,
+                 NS_ERROR_GFX_CMAP_MALFORMED);
+
+  const uint32_t numVarSelectorRecords =
+      ReadLongAt(aBuf, OffsetNumVarSelectorRecords);
+  NS_ENSURE_TRUE(
+      (tablelen - OffsetVarSelectorRecords) / SizeOfVarSelectorRecord >=
+          numVarSelectorRecords,
+      NS_ERROR_GFX_CMAP_MALFORMED);
+
+  const uint8_t* records = aBuf + OffsetVarSelectorRecords;
+  for (uint32_t i = 0; i < numVarSelectorRecords;
+       i++, records += SizeOfVarSelectorRecord) {
+    const uint32_t varSelector = ReadUint24At(records, VSRecOffsetVarSelector);
+    const uint32_t defUVSOffset = ReadLongAt(records, VSRecOffsetDefUVSOffset);
+    const uint32_t nonDefUVSOffset =
+        ReadLongAt(records, VSRecOffsetNonDefUVSOffset);
+    NS_ENSURE_TRUE(varSelector <= CMAP_MAX_CODEPOINT &&
+                       defUVSOffset <= tablelen - 4 &&
+                       nonDefUVSOffset <= tablelen - 4,
+                   NS_ERROR_GFX_CMAP_MALFORMED);
+
+    if (defUVSOffset) {
+      const uint32_t numUnicodeValueRanges = ReadLongAt(aBuf, defUVSOffset);
+      NS_ENSURE_TRUE((tablelen - defUVSOffset) / SizeOfDefUVSTable >=
+                         numUnicodeValueRanges,
+                     NS_ERROR_GFX_CMAP_MALFORMED);
+      const uint8_t* tables = aBuf + defUVSOffset + 4;
+      uint32_t prevEndUnicode = 0;
+      for (uint32_t j = 0; j < numUnicodeValueRanges;
+           j++, tables += SizeOfDefUVSTable) {
+        const uint32_t startUnicode =
+            ReadUint24At(tables, DefUVSOffsetStartUnicodeValue);
+        const uint32_t endUnicode =
+            startUnicode + tables[DefUVSOffsetAdditionalCount];
+        NS_ENSURE_TRUE((prevEndUnicode < startUnicode || j == 0) &&
+                           endUnicode <= CMAP_MAX_CODEPOINT,
+                       NS_ERROR_GFX_CMAP_MALFORMED);
+        prevEndUnicode = endUnicode;
+      }
+    }
+
+    if (nonDefUVSOffset) {
+      const uint32_t numUVSMappings = ReadLongAt(aBuf, nonDefUVSOffset);
+      NS_ENSURE_TRUE(
+          (tablelen - nonDefUVSOffset) / SizeOfNonDefUVSTable >= numUVSMappings,
+          NS_ERROR_GFX_CMAP_MALFORMED);
+      const uint8_t* tables = aBuf + nonDefUVSOffset + 4;
+      uint32_t prevUnicode = 0;
+      for (uint32_t j = 0; j < numUVSMappings;
+           j++, tables += SizeOfNonDefUVSTable) {
+        const uint32_t unicodeValue =
+            ReadUint24At(tables, NonDefUVSOffsetUnicodeValue);
+        NS_ENSURE_TRUE((prevUnicode < unicodeValue || j == 0) &&
+                           unicodeValue <= CMAP_MAX_CODEPOINT,
+                       NS_ERROR_GFX_CMAP_MALFORMED);
+        prevUnicode = unicodeValue;
+      }
+    }
+  }
+
+  uint8_t* table = new uint8_t[tablelen];
+  memcpy(table, aBuf, tablelen);
+
+  aTable = static_cast<const uint8_t*>(table);
+
+  return NS_OK;
+}
+
+// For fonts with two format-4 tables, the first one (Unicode platform) is
+// preferred on the Mac; on other platforms we allow the Microsoft-platform
+// subtable to replace it.
+
+#if defined(XP_MACOSX)
+#  define acceptableFormat4(p, e, k)                                         \
+    (((p) == PLATFORM_ID_MICROSOFT && (e) == EncodingIDMicrosoft && !(k)) || \
+     ((p) == PLATFORM_ID_UNICODE))
+
+#  define acceptableUCS4Encoding(p, e, k)           \
+    (((p) == PLATFORM_ID_MICROSOFT &&               \
+      (e) == EncodingIDUCS4ForMicrosoftPlatform) && \
+         (k) != 12 ||                               \
+     ((p) == PLATFORM_ID_UNICODE && ((e) != EncodingIDUVSForUnicodePlatform)))
+#else
+#  define acceptableFormat4(p, e, k)                                 \
+    (((p) == PLATFORM_ID_MICROSOFT && (e) == EncodingIDMicrosoft) || \
+     ((p) == PLATFORM_ID_UNICODE))
+
+#  define acceptableUCS4Encoding(p, e, k) \
+    ((p) == PLATFORM_ID_MICROSOFT && (e) == EncodingIDUCS4ForMicrosoftPlatform)
+#endif
+
+#define acceptablePlatform(p) \
+  ((p) == PLATFORM_ID_UNICODE || (p) == PLATFORM_ID_MICROSOFT)
+#define isSymbol(p, e) ((p) == PLATFORM_ID_MICROSOFT && (e) == EncodingIDSymbol)
+#define isUVSEncoding(p, e) \
+  ((p) == PLATFORM_ID_UNICODE && (e) == EncodingIDUVSForUnicodePlatform)
+
+uint32_t gfxFontUtils::FindPreferredSubtable(const uint8_t* aBuf,
+                                             uint32_t aBufLength,
+                                             uint32_t* aTableOffset,
+                                             uint32_t* aUVSTableOffset,
+                                             bool* aIsSymbolFont) {
+  enum {
+    OffsetVersion = 0,
+    OffsetNumTables = 2,
+    SizeOfHeader = 4,
+
+    TableOffsetPlatformID = 0,
+    TableOffsetEncodingID = 2,
+    TableOffsetOffset = 4,
+    SizeOfTable = 8,
+
+    SubtableOffsetFormat = 0
+  };
+  enum {
+    EncodingIDSymbol = 0,
+    EncodingIDMicrosoft = 1,
+    EncodingIDDefaultForUnicodePlatform = 0,
+    EncodingIDUCS4ForUnicodePlatform = 3,
+    EncodingIDUVSForUnicodePlatform = 5,
+    EncodingIDUCS4ForMicrosoftPlatform = 10
+  };
+
+  if (aUVSTableOffset) {
+    *aUVSTableOffset = 0;
+  }
+  if (aIsSymbolFont) {
+    *aIsSymbolFont = false;
+  }
+
+  if (!aBuf || aBufLength < SizeOfHeader) {
+    // cmap table is missing, or too small to contain header fields!
+    return 0;
+  }
+
+  // uint16_t version = ReadShortAt(aBuf, OffsetVersion); // Unused:
+  // self-documenting.
+  uint16_t numTables = ReadShortAt(aBuf, OffsetNumTables);
+  if (aBufLength < uint32_t(SizeOfHeader + numTables * SizeOfTable)) {
+    return 0;
+  }
+
+  // save the format we want here
+  uint32_t keepFormat = 0;
+
+  const uint8_t* table = aBuf + SizeOfHeader;
+  for (uint16_t i = 0; i < numTables; ++i, table += SizeOfTable) {
+    const uint16_t platformID = ReadShortAt(table, TableOffsetPlatformID);
+    if (!acceptablePlatform(platformID)) continue;
+
+    const uint16_t encodingID = ReadShortAt(table, TableOffsetEncodingID);
+    const uint32_t offset = ReadLongAt(table, TableOffsetOffset);
+    if (aBufLength - 2 < offset) {
+      // this subtable is not valid - beyond end of buffer
+      return 0;
+    }
+
+    const uint8_t* subtable = aBuf + offset;
+    const uint16_t format = ReadShortAt(subtable, SubtableOffsetFormat);
+
+    if (isSymbol(platformID, encodingID)) {
+      keepFormat = format;
+      *aTableOffset = offset;
+      if (aIsSymbolFont) {
+        *aIsSymbolFont = true;
+      }
+      break;
+    } else if (format == 4 &&
+               acceptableFormat4(platformID, encodingID, keepFormat)) {
+      keepFormat = format;
+      *aTableOffset = offset;
+    } else if ((format == 10 || format == 12 || format == 13) &&
+               acceptableUCS4Encoding(platformID, encodingID, keepFormat)) {
+      keepFormat = format;
+      *aTableOffset = offset;
+      if (platformID > PLATFORM_ID_UNICODE || !aUVSTableOffset ||
+          *aUVSTableOffset) {
+        break;  // we don't want to try anything else when this format is
+                // available.
+      }
+    } else if (format == 14 && isUVSEncoding(platformID, encodingID) &&
+               aUVSTableOffset) {
+      *aUVSTableOffset = offset;
+      if (keepFormat == 10 || keepFormat == 12) {
+        break;
+      }
+    }
+  }
+
+  return keepFormat;
+}
+
+nsresult gfxFontUtils::ReadCMAP(const uint8_t* aBuf, uint32_t aBufLength,
+                                gfxSparseBitSet& aCharacterMap,
+                                uint32_t& aUVSOffset) {
+  uint32_t offset;
+  bool isSymbolFont;
+  uint32_t format = FindPreferredSubtable(aBuf, aBufLength, &offset,
+                                          &aUVSOffset, &isSymbolFont);
+
+  switch (format) {
+    case 4:
+      return ReadCMAPTableFormat4(aBuf + offset, aBufLength - offset,
+                                  aCharacterMap, isSymbolFont);
+
+    case 10:
+      return ReadCMAPTableFormat10(aBuf + offset, aBufLength - offset,
+                                   aCharacterMap);
+
+    case 12:
+    case 13:
+      return ReadCMAPTableFormat12or13(aBuf + offset, aBufLength - offset,
+                                       aCharacterMap);
+
+    default:
+      break;
+  }
+
+  return NS_ERROR_FAILURE;
+}
+
+#pragma pack(1)
+
+typedef struct {
+  AutoSwap_PRUint16 format;
+  AutoSwap_PRUint16 length;
+  AutoSwap_PRUint16 language;
+  AutoSwap_PRUint16 segCountX2;
+  AutoSwap_PRUint16 searchRange;
+  AutoSwap_PRUint16 entrySelector;
+  AutoSwap_PRUint16 rangeShift;
+
+  AutoSwap_PRUint16 arrays[1];
+} Format4Cmap;
+
+typedef struct Format14Cmap {
+  AutoSwap_PRUint16 format;
+  AutoSwap_PRUint32 length;
+  AutoSwap_PRUint32 numVarSelectorRecords;
+
+  typedef struct {
+    AutoSwap_PRUint24 varSelector;
+    AutoSwap_PRUint32 defaultUVSOffset;
+    AutoSwap_PRUint32 nonDefaultUVSOffset;
+  } VarSelectorRecord;
+
+  VarSelectorRecord varSelectorRecords[1];
+} Format14Cmap;
+
+typedef struct NonDefUVSTable {
+  AutoSwap_PRUint32 numUVSMappings;
+
+  typedef struct {
+    AutoSwap_PRUint24 unicodeValue;
+    AutoSwap_PRUint16 glyphID;
+  } UVSMapping;
+
+  UVSMapping uvsMappings[1];
+} NonDefUVSTable;
+
+#pragma pack()
+
+uint32_t gfxFontUtils::MapCharToGlyphFormat4(const uint8_t* aBuf,
+                                             uint32_t aLength, char16_t aCh) {
+  const Format4Cmap* cmap4 = reinterpret_cast<const Format4Cmap*>(aBuf);
+
+  uint16_t segCount = (uint16_t)(cmap4->segCountX2) / 2;
+
+  const AutoSwap_PRUint16* endCodes = &cmap4->arrays[0];
+  const AutoSwap_PRUint16* startCodes = &cmap4->arrays[segCount + 1];
+  const AutoSwap_PRUint16* idDelta = &startCodes[segCount];
+  const AutoSwap_PRUint16* idRangeOffset = &idDelta[segCount];
+
+  // Sanity-check that the fixed-size arrays don't exceed the buffer.
+  const uint8_t* const limit = aBuf + aLength;
+  if ((const uint8_t*)(&idRangeOffset[segCount]) > limit) {
+    return 0;  // broken font, just bail out safely
+  }
+
+  // For most efficient binary search, we want to work on a range of segment
+  // indexes that is a power of 2 so that we can always halve it by shifting.
+  // So we find the largest power of 2 that is <= segCount.
+  // We will offset this range by segOffset so as to reach the end
+  // of the table, provided that doesn't put us beyond the target
+  // value from the outset.
+  uint32_t powerOf2 = mozilla::FindHighestBit(segCount);
+  uint32_t segOffset = segCount - powerOf2;
+  uint32_t idx = 0;
+
+  if (uint16_t(startCodes[segOffset]) <= aCh) {
+    idx = segOffset;
+  }
+
+  // Repeatedly halve the size of the range until we find the target group
+  while (powerOf2 > 1) {
+    powerOf2 >>= 1;
+    if (uint16_t(startCodes[idx + powerOf2]) <= aCh) {
+      idx += powerOf2;
+    }
+  }
+
+  if (aCh >= uint16_t(startCodes[idx]) && aCh <= uint16_t(endCodes[idx])) {
+    uint16_t result;
+    if (uint16_t(idRangeOffset[idx]) == 0) {
+      result = aCh;
+    } else {
+      uint16_t offset = aCh - uint16_t(startCodes[idx]);
+      const AutoSwap_PRUint16* glyphIndexTable =
+          (const AutoSwap_PRUint16*)((const char*)&idRangeOffset[idx] +
+                                     uint16_t(idRangeOffset[idx]));
+      if ((const uint8_t*)(glyphIndexTable + offset + 1) > limit) {
+        return 0;  // broken font, just bail out safely
+      }
+      result = glyphIndexTable[offset];
+    }
+
+    // Note that this is unsigned 16-bit arithmetic, and may wrap around
+    // (which is required behavior per spec)
+    result += uint16_t(idDelta[idx]);
+    return result;
+  }
+
+  return 0;
+}
+
+uint32_t gfxFontUtils::MapCharToGlyphFormat10(const uint8_t* aBuf,
+                                              uint32_t aCh) {
+  const Format10CmapHeader* cmap10 =
+      reinterpret_cast<const Format10CmapHeader*>(aBuf);
+
+  uint32_t startChar = cmap10->startCharCode;
+  uint32_t numChars = cmap10->numChars;
+
+  if (aCh < startChar || aCh >= startChar + numChars) {
+    return 0;
+  }
+
+  const AutoSwap_PRUint16* glyphs =
+      reinterpret_cast<const AutoSwap_PRUint16*>(cmap10 + 1);
+
+  uint16_t glyph = glyphs[aCh - startChar];
+  return glyph;
+}
+
+uint32_t gfxFontUtils::MapCharToGlyphFormat12or13(const uint8_t* aBuf,
+                                                  uint32_t aCh) {
+  // The only difference between formats 12 and 13 is the interpretation of
+  // the glyphId field. So the code here uses the same "Format12" structures,
+  // etc., to handle both subtable formats.
+
+  const Format12CmapHeader* cmap12 =
+      reinterpret_cast<const Format12CmapHeader*>(aBuf);
+
+  // We know that numGroups is within range for the subtable size
+  // because it was checked by ReadCMAPTableFormat12or13.
+  uint32_t numGroups = cmap12->numGroups;
+
+  // The array of groups immediately follows the subtable header.
+  const Format12Group* groups =
+      reinterpret_cast<const Format12Group*>(aBuf + sizeof(Format12CmapHeader));
+
+  // For most efficient binary search, we want to work on a range that
+  // is a power of 2 so that we can always halve it by shifting.
+  // So we find the largest power of 2 that is <= numGroups.
+  // We will offset this range by rangeOffset so as to reach the end
+  // of the table, provided that doesn't put us beyond the target
+  // value from the outset.
+  uint32_t powerOf2 = mozilla::FindHighestBit(numGroups);
+  uint32_t rangeOffset = numGroups - powerOf2;
+  uint32_t range = 0;
+  uint32_t startCharCode;
+
+  if (groups[rangeOffset].startCharCode <= aCh) {
+    range = rangeOffset;
+  }
+
+  // Repeatedly halve the size of the range until we find the target group
+  while (powerOf2 > 1) {
+    powerOf2 >>= 1;
+    if (groups[range + powerOf2].startCharCode <= aCh) {
+      range += powerOf2;
+    }
+  }
+
+  // Check if the character is actually present in the range and return
+  // the corresponding glyph ID. Here is where formats 12 and 13 interpret
+  // the startGlyphId (12) or glyphId (13) field differently
+  startCharCode = groups[range].startCharCode;
+  if (startCharCode <= aCh && groups[range].endCharCode >= aCh) {
+    return uint16_t(cmap12->format) == 12
+               ? uint16_t(groups[range].startGlyphId) + aCh - startCharCode
+               : uint16_t(groups[range].startGlyphId);
+  }
+
+  // Else it's not present, so return the .notdef glyph
+  return 0;
+}
+
+namespace {
+
+struct Format14CmapWrapper {
+  const Format14Cmap& mCmap14;
+  explicit Format14CmapWrapper(const Format14Cmap& cmap14) : mCmap14(cmap14) {}
+  uint32_t operator[](size_t index) const {
+    return mCmap14.varSelectorRecords[index].varSelector;
+  }
+};
+
+struct NonDefUVSTableWrapper {
+  const NonDefUVSTable& mTable;
+  explicit NonDefUVSTableWrapper(const NonDefUVSTable& table) : mTable(table) {}
+  uint32_t operator[](size_t index) const {
+    return mTable.uvsMappings[index].unicodeValue;
+  }
+};
+
+}  // namespace
+
+uint16_t gfxFontUtils::MapUVSToGlyphFormat14(const uint8_t* aBuf, uint32_t aCh,
+                                             uint32_t aVS) {
+  using mozilla::BinarySearch;
+  const Format14Cmap* cmap14 = reinterpret_cast<const Format14Cmap*>(aBuf);
+
+  size_t index;
+  if (!BinarySearch(Format14CmapWrapper(*cmap14), 0,
+                    cmap14->numVarSelectorRecords, aVS, &index)) {
+    return 0;
+  }
+
+  const uint32_t nonDefUVSOffset =
+      cmap14->varSelectorRecords[index].nonDefaultUVSOffset;
+  if (!nonDefUVSOffset) {
+    return 0;
+  }
+
+  const NonDefUVSTable* table =
+      reinterpret_cast<const NonDefUVSTable*>(aBuf + nonDefUVSOffset);
+
+  if (BinarySearch(NonDefUVSTableWrapper(*table), 0, table->numUVSMappings, aCh,
+                   &index)) {
+    return table->uvsMappings[index].glyphID;
+  }
+
+  return 0;
+}
+
+uint32_t gfxFontUtils::MapCharToGlyph(const uint8_t* aCmapBuf,
+                                      uint32_t aBufLength, uint32_t aUnicode,
+                                      uint32_t aVarSelector) {
+  uint32_t offset, uvsOffset;
+  bool isSymbolFont;
+  uint32_t format = FindPreferredSubtable(aCmapBuf, aBufLength, &offset,
+                                          &uvsOffset, &isSymbolFont);
+
+  uint32_t gid;
+  switch (format) {
+    case 4:
+      gid = aUnicode < UNICODE_BMP_LIMIT
+                ? MapCharToGlyphFormat4(aCmapBuf + offset, aBufLength - offset,
+                                        char16_t(aUnicode))
+                : 0;
+      if (!gid && isSymbolFont) {
+        if (auto pua = MapLegacySymbolFontCharToPUA(aUnicode)) {
+          gid = MapCharToGlyphFormat4(aCmapBuf + offset, aBufLength - offset,
+                                      pua);
+        }
+      }
+      break;
+    case 10:
+      gid = MapCharToGlyphFormat10(aCmapBuf + offset, aUnicode);
+      break;
+    case 12:
+    case 13:
+      gid = MapCharToGlyphFormat12or13(aCmapBuf + offset, aUnicode);
+      break;
+    default:
+      NS_WARNING("unsupported cmap format, glyphs will be missing");
+      gid = 0;
+  }
+
+  if (aVarSelector && uvsOffset && gid) {
+    uint32_t varGID = gfxFontUtils::MapUVSToGlyphFormat14(
+        aCmapBuf + uvsOffset, aUnicode, aVarSelector);
+    if (!varGID) {
+      aUnicode = gfxFontUtils::GetUVSFallback(aUnicode, aVarSelector);
+      if (aUnicode) {
+        switch (format) {
+          case 4:
+            if (aUnicode < UNICODE_BMP_LIMIT) {
+              varGID = MapCharToGlyphFormat4(
+                  aCmapBuf + offset, aBufLength - offset, char16_t(aUnicode));
+            }
+            break;
+          case 10:
+            varGID = MapCharToGlyphFormat10(aCmapBuf + offset, aUnicode);
+            break;
+          case 12:
+          case 13:
+            varGID = MapCharToGlyphFormat12or13(aCmapBuf + offset, aUnicode);
+            break;
+        }
+      }
+    }
+    if (varGID) {
+      gid = varGID;
+    }
+
+    // else the variation sequence was not supported, use default mapping
+    // of the character code alone
+  }
+
+  return gid;
+}
+
+void gfxFontUtils::ParseFontList(const nsACString& aFamilyList,
+                                 nsTArray<nsCString>& aFontList) {
+  const char kComma = ',';
+
+  // append each font name to the list
+  nsAutoCString fontname;
+  const char *p, *p_end;
+  aFamilyList.BeginReading(p);
+  aFamilyList.EndReading(p_end);
+
+  while (p < p_end) {
+    const char* nameStart = p;
+    while (++p != p_end && *p != kComma) /* nothing */
+      ;
+
+    // pull out a single name and clean out leading/trailing whitespace
+    fontname = Substring(nameStart, p);
+    fontname.CompressWhitespace(true, true);
+
+    // append it to the list if it's not empty
+    if (!fontname.IsEmpty()) {
+      aFontList.AppendElement(fontname);
+    }
+    ++p;
+  }
+}
+
+void gfxFontUtils::GetPrefsFontList(const char* aPrefName,
+                                    nsTArray<nsCString>& aFontList,
+                                    bool aLocalized) {
+  aFontList.Clear();
+
+  nsAutoCString fontlistValue;
+  nsresult rv = aLocalized
+                    ? Preferences::GetLocalizedCString(aPrefName, fontlistValue)
+                    : Preferences::GetCString(aPrefName, fontlistValue);
+  if (NS_FAILED(rv)) {
+    return;
+  }
+
+  ParseFontList(fontlistValue, aFontList);
+}
+
+// produce a unique font name that is (1) a valid Postscript name and (2) less
+// than 31 characters in length.  Using AddFontMemResourceEx on Windows fails
+// for names longer than 30 characters in length.
+
+#define MAX_B64_LEN 32
+
+nsresult gfxFontUtils::MakeUniqueUserFontName(nsAString& aName) {
+  nsCOMPtr<nsIUUIDGenerator> uuidgen =
+      do_GetService("@mozilla.org/uuid-generator;1");
+  NS_ENSURE_TRUE(uuidgen, NS_ERROR_OUT_OF_MEMORY);
+
+  nsID guid;
+
+  NS_ASSERTION(sizeof(guid) * 2 <= MAX_B64_LEN, "size of nsID has changed!");
+
+  nsresult rv = uuidgen->GenerateUUIDInPlace(&guid);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  char guidB64[MAX_B64_LEN] = {0};
+
+  if (!PL_Base64Encode(reinterpret_cast<char*>(&guid), sizeof(guid), guidB64))
+    return NS_ERROR_FAILURE;
+
+  // all b64 characters except for '/' are allowed in Postscript names, so
+  // convert / ==> -
+  char* p;
+  for (p = guidB64; *p; p++) {
+    if (*p == '/') *p = '-';
+  }
+
+  aName.AssignLiteral(u"uf");
+  aName.AppendASCII(guidB64);
+  return NS_OK;
+}
+
+// TrueType/OpenType table handling code
+
+// need byte aligned structs
+#pragma pack(1)
+
+// name table stores set of name record structures, followed by
+// large block containing all the strings.  name record offset and length
+// indicates the offset and length within that block.
+// http://www.microsoft.com/typography/otspec/name.htm
+struct NameRecordData {
+  uint32_t offset;
+  uint32_t length;
+};
+
+#pragma pack()
+
+static bool IsValidSFNTVersion(uint32_t version) {
+  // normally 0x00010000, CFF-style OT fonts == 'OTTO' and Apple TT fonts =
+  // 'true' 'typ1' is also possible for old Type 1 fonts in a SFNT container but
+  // not supported
+  return version == 0x10000 || version == TRUETYPE_TAG('O', 'T', 'T', 'O') ||
+         version == TRUETYPE_TAG('t', 'r', 'u', 'e');
+}
+
+gfxUserFontType gfxFontUtils::DetermineFontDataType(const uint8_t* aFontData,
+                                                    uint32_t aFontDataLength) {
+  // test for OpenType font data
+  // problem: EOT-Lite with 0x10000 length will look like TrueType!
+  if (aFontDataLength >= sizeof(SFNTHeader)) {
+    const SFNTHeader* sfntHeader =
+        reinterpret_cast<const SFNTHeader*>(aFontData);
+    uint32_t sfntVersion = sfntHeader->sfntVersion;
+    if (IsValidSFNTVersion(sfntVersion)) {
+      return GFX_USERFONT_OPENTYPE;
+    }
+  }
+
+  // test for WOFF or WOFF2
+  if (aFontDataLength >= sizeof(AutoSwap_PRUint32)) {
+    const AutoSwap_PRUint32* version =
+        reinterpret_cast<const AutoSwap_PRUint32*>(aFontData);
+    if (uint32_t(*version) == TRUETYPE_TAG('w', 'O', 'F', 'F')) {
+      return GFX_USERFONT_WOFF;
+    }
+    if (uint32_t(*version) == TRUETYPE_TAG('w', 'O', 'F', '2')) {
+      return GFX_USERFONT_WOFF2;
+    }
+  }
+
+  // tests for other formats here
+
+  return GFX_USERFONT_UNKNOWN;
+}
+
+static int DirEntryCmp(const void* aKey, const void* aItem) {
+  int32_t tag = *static_cast<const int32_t*>(aKey);
+  const TableDirEntry* entry = static_cast<const TableDirEntry*>(aItem);
+  return tag - int32_t(entry->tag);
+}
+
+/* static */
+TableDirEntry* gfxFontUtils::FindTableDirEntry(const void* aFontData,
+                                               uint32_t aTableTag) {
+  const SFNTHeader* header = reinterpret_cast<const SFNTHeader*>(aFontData);
+  const TableDirEntry* dir = reinterpret_cast<const TableDirEntry*>(header + 1);
+  return static_cast<TableDirEntry*>(
+      bsearch(&aTableTag, dir, uint16_t(header->numTables),
+              sizeof(TableDirEntry), DirEntryCmp));
+}
+
+/* static */
+hb_blob_t* gfxFontUtils::GetTableFromFontData(const void* aFontData,
+                                              uint32_t aTableTag) {
+  const TableDirEntry* dir = FindTableDirEntry(aFontData, aTableTag);
+  if (dir) {
+    return hb_blob_create(
+        reinterpret_cast<const char*>(aFontData) + dir->offset, dir->length,
+        HB_MEMORY_MODE_READONLY, nullptr, nullptr);
+  }
+  return nullptr;
+}
+
+nsresult gfxFontUtils::RenameFont(const nsAString& aName,
+                                  const uint8_t* aFontData,
+                                  uint32_t aFontDataLength,
+                                  FallibleTArray<uint8_t>* aNewFont) {
+  NS_ASSERTION(aNewFont, "null font data array");
+
+  uint64_t dataLength(aFontDataLength);
+
+  // new name table
+  static const uint32_t neededNameIDs[] = {NAME_ID_FAMILY, NAME_ID_STYLE,
+                                           NAME_ID_UNIQUE, NAME_ID_FULL,
+                                           NAME_ID_POSTSCRIPT};
+
+  // calculate new name table size
+  uint16_t nameCount = ArrayLength(neededNameIDs);
+
+  // leave room for null-terminator
+  uint32_t nameStrLength = (aName.Length() + 1) * sizeof(char16_t);
+  if (nameStrLength > 65535) {
+    // The name length _in bytes_ must fit in an unsigned short field;
+    // therefore, a name longer than this cannot be used.
+    return NS_ERROR_FAILURE;
+  }
+
+  // round name table size up to 4-byte multiple
+  uint32_t nameTableSize =
+      (sizeof(NameHeader) + sizeof(NameRecord) * nameCount + nameStrLength +
+       3) &
+      ~3;
+
+  if (dataLength + nameTableSize > UINT32_MAX) return NS_ERROR_FAILURE;
+
+  // bug 505386 - need to handle unpadded font length
+  uint32_t paddedFontDataSize = (aFontDataLength + 3) & ~3;
+  uint32_t adjFontDataSize = paddedFontDataSize + nameTableSize;
+
+  // create new buffer: old font data plus new name table
+  if (!aNewFont->AppendElements(adjFontDataSize, fallible))
+    return NS_ERROR_OUT_OF_MEMORY;
+
+  // copy the old font data
+  uint8_t* newFontData = reinterpret_cast<uint8_t*>(aNewFont->Elements());
+
+  // null the last four bytes in case the font length is not a multiple of 4
+  memset(newFontData + aFontDataLength, 0,
+         paddedFontDataSize - aFontDataLength);
+
+  // copy font data
+  memcpy(newFontData, aFontData, aFontDataLength);
+
+  // null out the last 4 bytes for checksum calculations
+  memset(newFontData + adjFontDataSize - 4, 0, 4);
+
+  NameHeader* nameHeader =
+      reinterpret_cast<NameHeader*>(newFontData + paddedFontDataSize);
+
+  // -- name header
+  nameHeader->format = 0;
+  nameHeader->count = nameCount;
+  nameHeader->stringOffset =
+      sizeof(NameHeader) + nameCount * sizeof(NameRecord);
+
+  // -- name records
+  uint32_t i;
+  NameRecord* nameRecord = reinterpret_cast<NameRecord*>(nameHeader + 1);
+
+  for (i = 0; i < nameCount; i++, nameRecord++) {
+    nameRecord->platformID = PLATFORM_ID_MICROSOFT;
+    nameRecord->encodingID = ENCODING_ID_MICROSOFT_UNICODEBMP;
+    nameRecord->languageID = LANG_ID_MICROSOFT_EN_US;
+    nameRecord->nameID = neededNameIDs[i];
+    nameRecord->offset = 0;
+    nameRecord->length = nameStrLength;
+  }
+
+  // -- string data, located after the name records, stored in big-endian form
+  char16_t* strData = reinterpret_cast<char16_t*>(nameRecord);
+
+  mozilla::NativeEndian::copyAndSwapToBigEndian(strData, aName.BeginReading(),
+                                                aName.Length());
+  strData[aName.Length()] = 0;  // add null termination
+
+  // adjust name table header to point to the new name table
+  SFNTHeader* sfntHeader = reinterpret_cast<SFNTHeader*>(newFontData);
+
+  // table directory entries begin immediately following SFNT header
+  TableDirEntry* dirEntry =
+      FindTableDirEntry(newFontData, TRUETYPE_TAG('n', 'a', 'm', 'e'));
+  // function only called if font validates, so this should always be true
+  MOZ_ASSERT(dirEntry, "attempt to rename font with no name table");
+
+  uint32_t numTables = sfntHeader->numTables;
+
+  // note: dirEntry now points to 'name' table record
+
+  // recalculate name table checksum
+  uint32_t checkSum = 0;
+  AutoSwap_PRUint32* nameData =
+      reinterpret_cast<AutoSwap_PRUint32*>(nameHeader);
+  AutoSwap_PRUint32* nameDataEnd = nameData + (nameTableSize >> 2);
+
+  while (nameData < nameDataEnd) checkSum = checkSum + *nameData++;
+
+  // adjust name table entry to point to new name table
+  dirEntry->offset = paddedFontDataSize;
+  dirEntry->length = nameTableSize;
+  dirEntry->checkSum = checkSum;
+
+  // fix up checksums
+  uint32_t checksum = 0;
+
+  // checksum for font = (checksum of header) + (checksum of tables)
+  uint32_t headerLen = sizeof(SFNTHeader) + sizeof(TableDirEntry) * numTables;
+  const AutoSwap_PRUint32* headerData =
+      reinterpret_cast<const AutoSwap_PRUint32*>(newFontData);
+
+  // header length is in bytes, checksum calculated in longwords
+  for (i = 0; i < (headerLen >> 2); i++, headerData++) {
+    checksum += *headerData;
+  }
+
+  uint32_t headOffset = 0;
+  dirEntry = reinterpret_cast<TableDirEntry*>(newFontData + sizeof(SFNTHeader));
+
+  for (i = 0; i < numTables; i++, dirEntry++) {
+    if (dirEntry->tag == TRUETYPE_TAG('h', 'e', 'a', 'd')) {
+      headOffset = dirEntry->offset;
+    }
+    checksum += dirEntry->checkSum;
+  }
+
+  NS_ASSERTION(headOffset != 0, "no head table for font");
+
+  HeadTable* headData = reinterpret_cast<HeadTable*>(newFontData + headOffset);
+
+  headData->checkSumAdjustment = HeadTable::HEAD_CHECKSUM_CALC_CONST - checksum;
+
+  return NS_OK;
+}
+
+// This is only called after the basic validity of the downloaded sfnt
+// data has been checked, so it should never fail to find the name table
+// (though it might fail to read it, if memory isn't available);
+// other checks here are just for extra paranoia.
+nsresult gfxFontUtils::GetFullNameFromSFNT(const uint8_t* aFontData,
+                                           uint32_t aLength,
+                                           nsACString& aFullName) {
+  aFullName = "(MISSING NAME)";  // should always get replaced
+
+  const TableDirEntry* dirEntry =
+      FindTableDirEntry(aFontData, TRUETYPE_TAG('n', 'a', 'm', 'e'));
+
+  // should never fail, as we're only called after font validation succeeded
+  NS_ENSURE_TRUE(dirEntry, NS_ERROR_NOT_AVAILABLE);
+
+  uint32_t len = dirEntry->length;
+  NS_ENSURE_TRUE(aLength > len && aLength - len >= dirEntry->offset,
+                 NS_ERROR_UNEXPECTED);
+
+  AutoHBBlob nameBlob(hb_blob_create((const char*)aFontData + dirEntry->offset,
+                                     len, HB_MEMORY_MODE_READONLY, nullptr,
+                                     nullptr));
+  nsresult rv = GetFullNameFromTable(nameBlob, aFullName);
+
+  return rv;
+}
+
+nsresult gfxFontUtils::GetFullNameFromTable(hb_blob_t* aNameTable,
+                                            nsACString& aFullName) {
+  nsAutoCString name;
+  nsresult rv = gfxFontUtils::ReadCanonicalName(
+      aNameTable, gfxFontUtils::NAME_ID_FULL, name);
+  if (NS_SUCCEEDED(rv) && !name.IsEmpty()) {
+    aFullName = name;
+    return NS_OK;
+  }
+  rv = gfxFontUtils::ReadCanonicalName(aNameTable, gfxFontUtils::NAME_ID_FAMILY,
+                                       name);
+  if (NS_SUCCEEDED(rv) && !name.IsEmpty()) {
+    nsAutoCString styleName;
+    rv = gfxFontUtils::ReadCanonicalName(
+        aNameTable, gfxFontUtils::NAME_ID_STYLE, styleName);
+    if (NS_SUCCEEDED(rv) && !styleName.IsEmpty()) {
+      name.Append(' ');
+      name.Append(styleName);
+      aFullName = name;
+    }
+    return NS_OK;
+  }
+
+  return NS_ERROR_NOT_AVAILABLE;
+}
+
+nsresult gfxFontUtils::GetFamilyNameFromTable(hb_blob_t* aNameTable,
+                                              nsACString& aFamilyName) {
+  nsAutoCString name;
+  nsresult rv = gfxFontUtils::ReadCanonicalName(
+      aNameTable, gfxFontUtils::NAME_ID_FAMILY, name);
+  if (NS_SUCCEEDED(rv) && !name.IsEmpty()) {
+    aFamilyName = name;
+    return NS_OK;
+  }
+  return NS_ERROR_NOT_AVAILABLE;
+}
+
+enum {
+#if defined(XP_MACOSX)
+  CANONICAL_LANG_ID = gfxFontUtils::LANG_ID_MAC_ENGLISH,
+  PLATFORM_ID = gfxFontUtils::PLATFORM_ID_MAC
+#else
+  CANONICAL_LANG_ID = gfxFontUtils::LANG_ID_MICROSOFT_EN_US,
+  PLATFORM_ID = gfxFontUtils::PLATFORM_ID_MICROSOFT
+#endif
+};
+
+nsresult gfxFontUtils::ReadNames(const char* aNameData, uint32_t aDataLen,
+                                 uint32_t aNameID, int32_t aPlatformID,
+                                 nsTArray<nsCString>& aNames) {
+  return ReadNames(aNameData, aDataLen, aNameID, LANG_ALL, aPlatformID, aNames);
+}
+
+nsresult gfxFontUtils::ReadCanonicalName(hb_blob_t* aNameTable,
+                                         uint32_t aNameID, nsCString& aName) {
+  uint32_t nameTableLen;
+  const char* nameTable = hb_blob_get_data(aNameTable, &nameTableLen);
+  return ReadCanonicalName(nameTable, nameTableLen, aNameID, aName);
+}
+
+nsresult gfxFontUtils::ReadCanonicalName(const char* aNameData,
+                                         uint32_t aDataLen, uint32_t aNameID,
+                                         nsCString& aName) {
+  nsresult rv;
+
+  nsTArray<nsCString> names;
+
+  // first, look for the English name (this will succeed 99% of the time)
+  rv = ReadNames(aNameData, aDataLen, aNameID, CANONICAL_LANG_ID, PLATFORM_ID,
+                 names);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // otherwise, grab names for all languages
+  if (names.Length() == 0) {
+    rv = ReadNames(aNameData, aDataLen, aNameID, LANG_ALL, PLATFORM_ID, names);
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+#if defined(XP_MACOSX)
+  // may be dealing with font that only has Microsoft name entries
+  if (names.Length() == 0) {
+    rv = ReadNames(aNameData, aDataLen, aNameID, LANG_ID_MICROSOFT_EN_US,
+                   PLATFORM_ID_MICROSOFT, names);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    // getting really desperate now, take anything!
+    if (names.Length() == 0) {
+      rv = ReadNames(aNameData, aDataLen, aNameID, LANG_ALL,
+                     PLATFORM_ID_MICROSOFT, names);
+      NS_ENSURE_SUCCESS(rv, rv);
+    }
+  }
+#endif
+
+  // return the first name (99.9% of the time names will
+  // contain a single English name)
+  if (names.Length()) {
+    aName.Assign(names[0]);
+    return NS_OK;
+  }
+
+  return NS_ERROR_FAILURE;
+}
+
+// Charsets to use for decoding Mac platform font names.
+// This table is sorted by {encoding, language}, with the wildcard "ANY" being
+// greater than any defined values for each field; we use a binary search on
+// both fields, and fall back to matching only encoding if necessary
+
+// Some "redundant" entries for specific combinations are included such as
+// encoding=roman, lang=english, in order that common entries will be found
+// on the first search.
+
+const uint16_t ANY = 0xffff;
+const gfxFontUtils::MacFontNameCharsetMapping
+    gfxFontUtils::gMacFontNameCharsets[] = {
+        {ENCODING_ID_MAC_ROMAN, LANG_ID_MAC_ENGLISH, MACINTOSH_ENCODING},
+        {ENCODING_ID_MAC_ROMAN, LANG_ID_MAC_ICELANDIC, X_USER_DEFINED_ENCODING},
+        {ENCODING_ID_MAC_ROMAN, LANG_ID_MAC_TURKISH, X_USER_DEFINED_ENCODING},
+        {ENCODING_ID_MAC_ROMAN, LANG_ID_MAC_POLISH, X_USER_DEFINED_ENCODING},
+        {ENCODING_ID_MAC_ROMAN, LANG_ID_MAC_ROMANIAN, X_USER_DEFINED_ENCODING},
+        {ENCODING_ID_MAC_ROMAN, LANG_ID_MAC_CZECH, X_USER_DEFINED_ENCODING},
+        {ENCODING_ID_MAC_ROMAN, LANG_ID_MAC_SLOVAK, X_USER_DEFINED_ENCODING},
+        {ENCODING_ID_MAC_ROMAN, ANY, MACINTOSH_ENCODING},
+        {ENCODING_ID_MAC_JAPANESE, LANG_ID_MAC_JAPANESE, SHIFT_JIS_ENCODING},
+        {ENCODING_ID_MAC_JAPANESE, ANY, SHIFT_JIS_ENCODING},
+        {ENCODING_ID_MAC_TRAD_CHINESE, LANG_ID_MAC_TRAD_CHINESE, BIG5_ENCODING},
+        {ENCODING_ID_MAC_TRAD_CHINESE, ANY, BIG5_ENCODING},
+        {ENCODING_ID_MAC_KOREAN, LANG_ID_MAC_KOREAN, EUC_KR_ENCODING},
+        {ENCODING_ID_MAC_KOREAN, ANY, EUC_KR_ENCODING},
+        {ENCODING_ID_MAC_ARABIC, LANG_ID_MAC_ARABIC, X_USER_DEFINED_ENCODING},
+        {ENCODING_ID_MAC_ARABIC, LANG_ID_MAC_URDU, X_USER_DEFINED_ENCODING},
+        {ENCODING_ID_MAC_ARABIC, LANG_ID_MAC_FARSI, X_USER_DEFINED_ENCODING},
+        {ENCODING_ID_MAC_ARABIC, ANY, X_USER_DEFINED_ENCODING},
+        {ENCODING_ID_MAC_HEBREW, LANG_ID_MAC_HEBREW, X_USER_DEFINED_ENCODING},
+        {ENCODING_ID_MAC_HEBREW, ANY, X_USER_DEFINED_ENCODING},
+        {ENCODING_ID_MAC_GREEK, ANY, X_USER_DEFINED_ENCODING},
+        {ENCODING_ID_MAC_CYRILLIC, ANY, X_MAC_CYRILLIC_ENCODING},
+        {ENCODING_ID_MAC_DEVANAGARI, ANY, X_USER_DEFINED_ENCODING},
+        {ENCODING_ID_MAC_GURMUKHI, ANY, X_USER_DEFINED_ENCODING},
+        {ENCODING_ID_MAC_GUJARATI, ANY, X_USER_DEFINED_ENCODING},
+        {ENCODING_ID_MAC_SIMP_CHINESE, LANG_ID_MAC_SIMP_CHINESE,
+         GB18030_ENCODING},
+        {ENCODING_ID_MAC_SIMP_CHINESE, ANY, GB18030_ENCODING}};
+
+const Encoding* gfxFontUtils::gISOFontNameCharsets[] = {
+    /* 0 */ WINDOWS_1252_ENCODING, /* US-ASCII */
+    /* 1 */ nullptr, /* spec says "ISO 10646" but does not specify encoding
+                        form! */
+    /* 2 */ WINDOWS_1252_ENCODING /* ISO-8859-1 */
+};
+
+const Encoding* gfxFontUtils::gMSFontNameCharsets[] = {
+    /* [0] ENCODING_ID_MICROSOFT_SYMBOL */ UTF_16BE_ENCODING,
+    /* [1] ENCODING_ID_MICROSOFT_UNICODEBMP */ UTF_16BE_ENCODING,
+    /* [2] ENCODING_ID_MICROSOFT_SHIFTJIS */ SHIFT_JIS_ENCODING,
+    /* [3] ENCODING_ID_MICROSOFT_PRC */ nullptr,
+    /* [4] ENCODING_ID_MICROSOFT_BIG5 */ BIG5_ENCODING,
+    /* [5] ENCODING_ID_MICROSOFT_WANSUNG */ nullptr,
+    /* [6] ENCODING_ID_MICROSOFT_JOHAB */ nullptr,
+    /* [7] reserved */ nullptr,
+    /* [8] reserved */ nullptr,
+    /* [9] reserved */ nullptr,
+    /*[10] ENCODING_ID_MICROSOFT_UNICODEFULL */ UTF_16BE_ENCODING};
+
+struct MacCharsetMappingComparator {
+  typedef gfxFontUtils::MacFontNameCharsetMapping MacFontNameCharsetMapping;
+  const MacFontNameCharsetMapping& mSearchValue;
+  explicit MacCharsetMappingComparator(
+      const MacFontNameCharsetMapping& aSearchValue)
+      : mSearchValue(aSearchValue) {}
+  int operator()(const MacFontNameCharsetMapping& aEntry) const {
+    if (mSearchValue < aEntry) {
+      return -1;
+    }
+    if (aEntry < mSearchValue) {
+      return 1;
+    }
+    return 0;
+  }
+};
+
+// Return the Encoding object we should use to decode a font name
+// given the name table attributes.
+// Special return values:
+//    X_USER_DEFINED_ENCODING  One of Mac legacy encodings that is not a part
+//                             of Encoding Standard
+//    nullptr                  unknown charset, do not attempt conversion
+const Encoding* gfxFontUtils::GetCharsetForFontName(uint16_t aPlatform,
+                                                    uint16_t aScript,
+                                                    uint16_t aLanguage) {
+  switch (aPlatform) {
+    case PLATFORM_ID_UNICODE:
+      return UTF_16BE_ENCODING;
+
+    case PLATFORM_ID_MAC: {
+      MacFontNameCharsetMapping searchValue = {aScript, aLanguage, nullptr};
+      for (uint32_t i = 0; i < 2; ++i) {
+        size_t idx;
+        if (BinarySearchIf(gMacFontNameCharsets, 0,
+                           ArrayLength(gMacFontNameCharsets),
+                           MacCharsetMappingComparator(searchValue), &idx)) {
+          return gMacFontNameCharsets[idx].mEncoding;
+        }
+
+        // no match, so try again finding one in any language
+        searchValue.mLanguage = ANY;
+      }
+    } break;
+
+    case PLATFORM_ID_ISO:
+      if (aScript < ArrayLength(gISOFontNameCharsets)) {
+        return gISOFontNameCharsets[aScript];
+      }
+      break;
+
+    case PLATFORM_ID_MICROSOFT:
+      if (aScript < ArrayLength(gMSFontNameCharsets)) {
+        return gMSFontNameCharsets[aScript];
+      }
+      break;
+  }
+
+  return nullptr;
+}
+
+template <int N>
+static bool StartsWith(const nsACString& string, const char (&prefix)[N]) {
+  if (N - 1 > string.Length()) {
+    return false;
+  }
+  return memcmp(string.Data(), prefix, N - 1) == 0;
+}
+
+// convert a raw name from the name table to an nsString, if possible;
+// return value indicates whether conversion succeeded
+bool gfxFontUtils::DecodeFontName(const char* aNameData, int32_t aByteLen,
+                                  uint32_t aPlatformCode, uint32_t aScriptCode,
+                                  uint32_t aLangCode, nsACString& aName) {
+  if (aByteLen <= 0) {
+    NS_WARNING("empty font name");
+    aName.SetLength(0);
+    return true;
+  }
+
+  auto encoding = GetCharsetForFontName(aPlatformCode, aScriptCode, aLangCode);
+
+  if (!encoding) {
+    // nullptr -> unknown charset
+#ifdef DEBUG
+    char warnBuf[128];
+    if (aByteLen > 64) aByteLen = 64;
+    SprintfLiteral(warnBuf,
+                   "skipping font name, unknown charset %d:%d:%d for <%.*s>",
+                   aPlatformCode, aScriptCode, aLangCode, aByteLen, aNameData);
+    NS_WARNING(warnBuf);
+#endif
+    return false;
+  }
+
+  if (encoding == X_USER_DEFINED_ENCODING) {
+#ifdef XP_MACOSX
+    // Special case for macOS only: support legacy Mac encodings
+    // that aren't part of the Encoding Standard.
+    if (aPlatformCode == PLATFORM_ID_MAC) {
+      CFStringRef str =
+          CFStringCreateWithBytes(kCFAllocatorDefault, (const UInt8*)aNameData,
+                                  aByteLen, aScriptCode, false);
+      if (str) {
+        CFIndex length = CFStringGetLength(str);
+        nsAutoString name16;
+        name16.SetLength(length);
+        CFStringGetCharacters(str, CFRangeMake(0, length),
+                              (UniChar*)name16.BeginWriting());
+        CFRelease(str);
+        CopyUTF16toUTF8(name16, aName);
+        return true;
+      }
+    }
+#endif
+    NS_WARNING("failed to get the decoder for a font name string");
+    return false;
+  }
+
+  auto rv = encoding->DecodeWithoutBOMHandling(
+      nsDependentCSubstring(aNameData, aByteLen), aName);
+  return NS_SUCCEEDED(rv);
+}
+
+nsresult gfxFontUtils::ReadNames(const char* aNameData, uint32_t aDataLen,
+                                 uint32_t aNameID, int32_t aLangID,
+                                 int32_t aPlatformID,
+                                 nsTArray<nsCString>& aNames) {
+  NS_ASSERTION(aDataLen != 0, "null name table");
+
+  if (!aDataLen) {
+    return NS_ERROR_FAILURE;
+  }
+
+  // -- name table data
+  const NameHeader* nameHeader = reinterpret_cast<const NameHeader*>(aNameData);
+
+  uint32_t nameCount = nameHeader->count;
+
+  // -- sanity check the number of name records
+  if (uint64_t(nameCount) * sizeof(NameRecord) > aDataLen) {
+    NS_WARNING("invalid font (name table data)");
+    return NS_ERROR_FAILURE;
+  }
+
+  // -- iterate through name records
+  const NameRecord* nameRecord =
+      reinterpret_cast<const NameRecord*>(aNameData + sizeof(NameHeader));
+  uint64_t nameStringsBase = uint64_t(nameHeader->stringOffset);
+
+  uint32_t i;
+  for (i = 0; i < nameCount; i++, nameRecord++) {
+    uint32_t platformID;
+
+    // skip over unwanted nameID's
+    if (uint32_t(nameRecord->nameID) != aNameID) {
+      continue;
+    }
+
+    // skip over unwanted platform data
+    platformID = nameRecord->platformID;
+    if (aPlatformID != PLATFORM_ALL && platformID != uint32_t(aPlatformID)) {
+      continue;
+    }
+
+    // skip over unwanted languages
+    if (aLangID != LANG_ALL &&
+        uint32_t(nameRecord->languageID) != uint32_t(aLangID)) {
+      continue;
+    }
+
+    // add name to names array
+
+    // -- calculate string location
+    uint32_t namelen = nameRecord->length;
+    uint32_t nameoff =
+        nameRecord->offset;  // offset from base of string storage
+
+    if (nameStringsBase + uint64_t(nameoff) + uint64_t(namelen) > aDataLen) {
+      NS_WARNING("invalid font (name table strings)");
+      return NS_ERROR_FAILURE;
+    }
+
+    // -- decode if necessary and make nsString
+    nsAutoCString name;
+
+    DecodeFontName(aNameData + nameStringsBase + nameoff, namelen, platformID,
+                   uint32_t(nameRecord->encodingID),
+                   uint32_t(nameRecord->languageID), name);
+
+    uint32_t k, numNames;
+    bool foundName = false;
+
+    numNames = aNames.Length();
+    for (k = 0; k < numNames; k++) {
+      if (name.Equals(aNames[k])) {
+        foundName = true;
+        break;
+      }
+    }
+
+    if (!foundName) aNames.AppendElement(name);
+  }
+
+  return NS_OK;
+}
+
+void gfxFontUtils::GetVariationData(
+    gfxFontEntry* aFontEntry, nsTArray<gfxFontVariationAxis>* aAxes,
+    nsTArray<gfxFontVariationInstance>* aInstances) {
+  MOZ_ASSERT(!aAxes || aAxes->IsEmpty());
+  MOZ_ASSERT(!aInstances || aInstances->IsEmpty());
+
+  if (!aFontEntry->HasVariations()) {
+    return;
+  }
+
+  // Some platforms don't offer a simple API to return the list of instances,
+  // so we have to interpret the 'fvar' table ourselves.
+
+  // https://www.microsoft.com/typography/otspec/fvar.htm#fvarHeader
+  struct FvarHeader {
+    AutoSwap_PRUint16 majorVersion;
+    AutoSwap_PRUint16 minorVersion;
+    AutoSwap_PRUint16 axesArrayOffset;
+    AutoSwap_PRUint16 reserved;
+    AutoSwap_PRUint16 axisCount;
+    AutoSwap_PRUint16 axisSize;
+    AutoSwap_PRUint16 instanceCount;
+    AutoSwap_PRUint16 instanceSize;
+  };
+
+  // https://www.microsoft.com/typography/otspec/fvar.htm#variationAxisRecord
+  struct AxisRecord {
+    AutoSwap_PRUint32 axisTag;
+    AutoSwap_PRInt32 minValue;
+    AutoSwap_PRInt32 defaultValue;
+    AutoSwap_PRInt32 maxValue;
+    AutoSwap_PRUint16 flags;
+    AutoSwap_PRUint16 axisNameID;
+  };
+  const uint16_t HIDDEN_AXIS = 0x0001;  // AxisRecord flags value
+
+  // https://www.microsoft.com/typography/otspec/fvar.htm#instanceRecord
+  struct InstanceRecord {
+    AutoSwap_PRUint16 subfamilyNameID;
+    AutoSwap_PRUint16 flags;
+    AutoSwap_PRInt32 coordinates[1];  // variable-size array [axisCount]
+    // The variable-length 'coordinates' array may be followed by an
+    // optional extra field 'postScriptNameID'. We can't directly
+    // represent this in the struct, because its offset varies depending
+    // on the number of axes present.
+    // (Not currently used by our code here anyhow.)
+    //  AutoSwap_PRUint16 postScriptNameID;
+  };
+
+  // Load the two font tables we need as harfbuzz blobs; if either is absent,
+  // just bail out.
+  AutoHBBlob fvarTable(
+      aFontEntry->GetFontTable(TRUETYPE_TAG('f', 'v', 'a', 'r')));
+  AutoHBBlob nameTable(
+      aFontEntry->GetFontTable(TRUETYPE_TAG('n', 'a', 'm', 'e')));
+  if (!fvarTable || !nameTable) {
+    return;
+  }
+  unsigned int len;
+  const char* data = hb_blob_get_data(fvarTable, &len);
+  if (len < sizeof(FvarHeader)) {
+    return;
+  }
+  // Read the fields of the table header; bail out if it looks broken.
+  auto fvar = reinterpret_cast<const FvarHeader*>(data);
+  if (uint16_t(fvar->majorVersion) != 1 || uint16_t(fvar->minorVersion) != 0 ||
+      uint16_t(fvar->reserved) != 2) {
+    return;
+  }
+  uint16_t axisCount = fvar->axisCount;
+  uint16_t axisSize = fvar->axisSize;
+  uint16_t instanceCount = fvar->instanceCount;
+  uint16_t instanceSize = fvar->instanceSize;
+  if (axisCount ==
+          0 ||  // no axes?
+                // https://www.microsoft.com/typography/otspec/fvar.htm#axisSize
+      axisSize != 20 ||  // required value for current table version
+      // https://www.microsoft.com/typography/otspec/fvar.htm#instanceSize
+      (instanceSize != axisCount * sizeof(int32_t) + 4 &&
+       instanceSize != axisCount * sizeof(int32_t) + 6)) {
+    return;
+  }
+  // Check that axis array will not exceed table size
+  uint16_t axesOffset = fvar->axesArrayOffset;
+  if (axesOffset + uint32_t(axisCount) * axisSize > len) {
+    return;
+  }
+  // Get pointer to the array of axis records
+  auto axes = reinterpret_cast<const AxisRecord*>(data + axesOffset);
+  // Get address of instance array, and check it doesn't overflow table size.
+  // https://www.microsoft.com/typography/otspec/fvar.htm#axisAndInstanceArrays
+  auto instData = data + axesOffset + axisCount * axisSize;
+  if (instData + uint32_t(instanceCount) * instanceSize > data + len) {
+    return;
+  }
+  if (aInstances) {
+    aInstances->SetCapacity(instanceCount);
+    for (unsigned i = 0; i < instanceCount; ++i, instData += instanceSize) {
+      // Typed pointer to the current instance record, to read its fields.
+      auto inst = reinterpret_cast<const InstanceRecord*>(instData);
+      // Pointer to the coordinates array within the instance record.
+      // This array has axisCount elements, and is included in instanceSize
+      // (which depends on axisCount, and was validated above) so we know
+      // access to coords[j] below will not be outside the table bounds.
+      auto coords = &inst->coordinates[0];
+      gfxFontVariationInstance instance;
+      uint16_t nameID = inst->subfamilyNameID;
+      nsresult rv = ReadCanonicalName(nameTable, nameID, instance.mName);
+      if (NS_FAILED(rv)) {
+        // If no name was available for the instance, ignore it.
+        continue;
+      }
+      instance.mValues.SetCapacity(axisCount);
+      for (unsigned j = 0; j < axisCount; ++j) {
+        gfxFontVariationValue value = {axes[j].axisTag,
+                                       int32_t(coords[j]) / 65536.0f};
+        instance.mValues.AppendElement(value);
+      }
+      aInstances->AppendElement(std::move(instance));
+    }
+  }
+  if (aAxes) {
+    aAxes->SetCapacity(axisCount);
+    for (unsigned i = 0; i < axisCount; ++i) {
+      if (uint16_t(axes[i].flags) & HIDDEN_AXIS) {
+        continue;
+      }
+      gfxFontVariationAxis axis;
+      axis.mTag = axes[i].axisTag;
+      uint16_t nameID = axes[i].axisNameID;
+      nsresult rv = ReadCanonicalName(nameTable, nameID, axis.mName);
+      if (NS_FAILED(rv)) {
+        axis.mName.Truncate(0);
+      }
+      // Convert values from 16.16 fixed-point to float
+      axis.mMinValue = int32_t(axes[i].minValue) / 65536.0f;
+      axis.mDefaultValue = int32_t(axes[i].defaultValue) / 65536.0f;
+      axis.mMaxValue = int32_t(axes[i].maxValue) / 65536.0f;
+      aAxes->AppendElement(axis);
+    }
+  }
+}
+
+void gfxFontUtils::ReadOtherFamilyNamesForFace(
+    const nsACString& aFamilyName, const char* aNameData, uint32_t aDataLength,
+    nsTArray<nsCString>& aOtherFamilyNames, bool useFullName) {
+  const NameHeader* nameHeader = reinterpret_cast<const NameHeader*>(aNameData);
+
+  uint32_t nameCount = nameHeader->count;
+  if (nameCount * sizeof(NameRecord) > aDataLength) {
+    NS_WARNING("invalid font (name records)");
+    return;
+  }
+
+  const NameRecord* nameRecord =
+      reinterpret_cast<const NameRecord*>(aNameData + sizeof(NameHeader));
+  uint32_t stringsBase = uint32_t(nameHeader->stringOffset);
+
+  for (uint32_t i = 0; i < nameCount; i++, nameRecord++) {
+    uint32_t nameLen = nameRecord->length;
+    uint32_t nameOff =
+        nameRecord->offset;  // offset from base of string storage
+
+    if (stringsBase + nameOff + nameLen > aDataLength) {
+      NS_WARNING("invalid font (name table strings)");
+      return;
+    }
+
+    uint16_t nameID = nameRecord->nameID;
+    if ((useFullName && nameID == NAME_ID_FULL) ||
+        (!useFullName &&
+         (nameID == NAME_ID_FAMILY || nameID == NAME_ID_PREFERRED_FAMILY))) {
+      nsAutoCString otherFamilyName;
+      bool ok = DecodeFontName(
+          aNameData + stringsBase + nameOff, nameLen,
+          uint32_t(nameRecord->platformID), uint32_t(nameRecord->encodingID),
+          uint32_t(nameRecord->languageID), otherFamilyName);
+      // add if not same as canonical family name
+      if (ok && otherFamilyName != aFamilyName &&
+          !aOtherFamilyNames.Contains(otherFamilyName)) {
+        aOtherFamilyNames.AppendElement(otherFamilyName);
+      }
+    }
+  }
+}
+
+#ifdef XP_WIN
+
+/* static */
+bool gfxFontUtils::IsCffFont(const uint8_t* aFontData) {
+  // this is only called after aFontData has passed basic validation,
+  // so we know there is enough data present to allow us to read the version!
+  const SFNTHeader* sfntHeader = reinterpret_cast<const SFNTHeader*>(aFontData);
+  return (sfntHeader->sfntVersion == TRUETYPE_TAG('O', 'T', 'T', 'O'));
+}
+
+#endif
+
+/* static */ bool gfxFontUtils::IsInServoTraversal() {
+  if (NS_IsMainThread()) {
+    return ServoStyleSet::IsInServoTraversal();
+  }
+
+  if (dom::GetCurrentThreadWorkerPrivate()) {
+    return false;
+  }
+
+  // The only permissible threads are the main thread, the worker thread, the
+  // servo threads. If the latter, we must be traversing.
+  bool traversing = ServoStyleSet::IsInServoTraversal();
+  MOZ_ASSERT(traversing);
+  return traversing;
+}
+
+/* static */ ServoStyleSet* gfxFontUtils::CurrentServoStyleSet() {
+  // If we are on a worker thread, we must not check for the current set since
+  // the main/servo threads may be busy in parallel.
+  if (dom::GetCurrentThreadWorkerPrivate()) {
+    return nullptr;
+  }
+
+  return ServoStyleSet::Current();
+}
+
+#ifdef DEBUG
+/* static */ void gfxFontUtils::AssertSafeThreadOrServoFontMetricsLocked() {
+  if (!dom::GetCurrentThreadWorkerPrivate()) {
+    AssertIsMainThreadOrServoFontMetricsLocked();
+  }
+}
+#endif
+
+#undef acceptablePlatform
+#undef isSymbol
+#undef isUVSEncoding
+#undef LOG
+#undef LOG_ENABLED