Use font.name-list.emoji preference for emoji presenration.

1 files changed, 18 insertions, 5 deletions

diff --git a/gfx/thebes/gfxTextRun.cpp b/gfx/thebes/gfxTextRun.cpp
index 6718eed01..45ea7e6d0 100644
--- a/gfx/thebes/gfxTextRun.cpp
+++ b/gfx/thebes/gfxTextRun.cpp
@@ -45,6 +45,9 @@ using mozilla::services::GetObserverService;
 static const char16_t kEllipsisChar[] = { 0x2026, 0x0 };
 static const char16_t kASCIIPeriodsChar[] = { '.', '.', '.', 0x0 };
 
+const uint32_t kVariationSelector15 = 0xFE0E; // text presentation
+const uint32_t kVariationSelector16 = 0xFE0F; // emoji presentation
+
 #ifdef DEBUG_roc
 #define DEBUG_TEXT_RUN_STORAGE_METRICS
 #endif
@@ -2813,7 +2816,7 @@ gfxFontGroup::FindFontForChar(uint32_t aCh, uint32_t aPrevCh, uint32_t aNextCh,
         return nullptr;
 
     // 2. search pref fonts
-    RefPtr<gfxFont> font = WhichPrefFontSupportsChar(aCh);
+    RefPtr<gfxFont> font = WhichPrefFontSupportsChar(aCh, aNextCh);
     if (font) {
         *aMatchType = gfxTextRange::kPrefsFallback;
         return font.forget();
@@ -3081,15 +3084,25 @@ gfxFontGroup::ContainsUserFont(const gfxUserFontEntry* aUserFont)
 }
 
 already_AddRefed<gfxFont>
-gfxFontGroup::WhichPrefFontSupportsChar(uint32_t aCh)
+gfxFontGroup::WhichPrefFontSupportsChar(uint32_t aCh, uint32_t aNextCh)
 {
     RefPtr<gfxFont> font;
 
-    // get the pref font list if it hasn't been set up already
-    uint32_t unicodeRange = FindCharUnicodeRange(aCh);
+    eFontPrefLang charLang;
     gfxPlatformFontList* pfl = gfxPlatformFontList::PlatformFontList();
-    eFontPrefLang charLang = pfl->GetFontPrefLangFor(unicodeRange);
 
+    EmojiPresentation emoji = GetEmojiPresentation(aCh);
+    if ((emoji != EmojiPresentation::TextOnly &&
+         (aNextCh == kVariationSelector16 ||
+          (emoji == EmojiPresentation::EmojiDefault &&
+           aNextCh != kVariationSelector15)))) {
+        charLang = eFontPrefLang_Emoji;
+    } else {
+        // get the pref font list if it hasn't been set up already
+        uint32_t unicodeRange = FindCharUnicodeRange(aCh);
+        charLang = pfl->GetFontPrefLangFor(unicodeRange);
+    }
+ 
     // if the last pref font was the first family in the pref list, no need to recheck through a list of families
     if (mLastPrefFont && charLang == mLastPrefLang &&
         mLastPrefFirstFont && mLastPrefFont->HasCharacter(aCh)) {