diff -r 000000000000 -r 6474c204b198 gfx/thebes/gfxGDIShaper.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gfx/thebes/gfxGDIShaper.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,96 @@
+/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ * 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/. */
+
+//#define FORCE_PR_LOG
+
+#include "gfxGDIShaper.h"
+
+/**********************************************************************
+ *
+ * class gfxGDIShaper
+ *
+ **********************************************************************/
+
+bool
+gfxGDIShaper::ShapeText(gfxContext      *aContext,
+                        const char16_t *aText,
+                        uint32_t         aOffset,
+                        uint32_t         aLength,
+                        int32_t          aScript,
+                        gfxShapedText   *aShapedText)
+{
+    DCFromContext dc(aContext);
+    AutoSelectFont selectFont(dc, static_cast<gfxGDIFont*>(mFont)->GetHFONT());
+
+    uint32_t length = aLength;
+    AutoFallibleTArray<WORD,500> glyphArray;
+    if (!glyphArray.SetLength(length)) {
+        return false;
+    }
+    WORD *glyphs = glyphArray.Elements();
+
+    DWORD ret = ::GetGlyphIndicesW(dc, char16ptr_t(aText), length,
+                                   glyphs, GGI_MARK_NONEXISTING_GLYPHS);
+    if (ret == GDI_ERROR) {
+        return false;
+    }
+
+    for (int k = 0; k < length; k++) {
+        if (glyphs[k] == 0xFFFF)
+            return false;
+    }
+ 
+    SIZE size;
+    AutoFallibleTArray<int,500> partialWidthArray;
+    if (!partialWidthArray.SetLength(length)) {
+        return false;
+    }
+
+    BOOL success = ::GetTextExtentExPointI(dc,
+                                           glyphs,
+                                           length,
+                                           INT_MAX,
+                                           nullptr,
+                                           partialWidthArray.Elements(),
+                                           &size);
+    if (!success) {
+        return false;
+    }
+
+    gfxTextRun::CompressedGlyph g;
+    gfxTextRun::CompressedGlyph *charGlyphs =
+        aShapedText->GetCharacterGlyphs();
+    uint32_t i;
+    int32_t lastWidth = 0;
+    int32_t appUnitsPerDevPixel = aShapedText->GetAppUnitsPerDevUnit();
+    for (i = 0; i < length; ++i) {
+        uint32_t offset = aOffset + i;
+        int32_t advancePixels = partialWidthArray[i] - lastWidth;
+        lastWidth = partialWidthArray[i];
+        int32_t advanceAppUnits = advancePixels * appUnitsPerDevPixel;
+        WCHAR glyph = glyphs[i];
+        NS_ASSERTION(!gfxFontGroup::IsInvalidChar(aText[i]),
+                     "Invalid character detected!");
+        bool atClusterStart = charGlyphs[offset].IsClusterStart();
+        if (advanceAppUnits >= 0 &&
+            gfxShapedWord::CompressedGlyph::IsSimpleAdvance(advanceAppUnits) &&
+            gfxShapedWord::CompressedGlyph::IsSimpleGlyphID(glyph) &&
+            atClusterStart)
+        {
+            charGlyphs[offset].SetSimpleGlyph(advanceAppUnits, glyph);
+        } else {
+            gfxShapedText::DetailedGlyph details;
+            details.mGlyphID = glyph;
+            details.mAdvance = advanceAppUnits;
+            details.mXOffset = 0;
+            details.mYOffset = 0;
+            aShapedText->SetGlyphs(offset,
+                                   g.SetComplex(atClusterStart, true, 1),
+                                   &details);
+        }
+    }
+
+    return true;
+}