Bug 1108616 - part 3 - Only do language-specific shaping when the language was explicitly tagged. r=jdaggett

gfx/thebes/gfxFont.cpp

@@ -2896,7 +2896,8 @@ gfxFont::InitFakeSmallCapsRun(gfxContext     *aContext,
                 } else if (ch != ToLowerCase(ch)) {
                     // ch is upper case
                     chAction = (aSyntheticUpper ? kUppercaseReduce : kNoChange);
-                    if (mStyle.language == nsGkAtoms::el) {
+                    if (mStyle.explicitLanguage &&
+                        mStyle.language == nsGkAtoms::el) {
                         // In Greek, check for characters that will be modified by
                         // the GreekUpperCase mapping - this catches accented
                         // capitals where the accent is to be removed (bug 307039).
@@ -2948,7 +2949,8 @@ gfxFont::InitFakeSmallCapsRun(gfxContext     *aContext,
                     TransformString(origString,
                                     convertedString,
                                     true,
-                                    mStyle.language,
+                                    mStyle.explicitLanguage
+                                      ? mStyle.language : nullptr,
                                     charsToMergeArray,
                                     deletedCharsArray);
 

gfx/thebes/gfxGraphiteShaper.cpp

@@ -145,7 +145,7 @@ gfxGraphiteShaper::ShapeText(gfxContext      *aContext,
         grLang = MakeGraphiteLangTag(style->languageOverride);
     } else if (entry->mLanguageOverride) {
         grLang = MakeGraphiteLangTag(entry->mLanguageOverride);
-    } else {
+    } else if (style->explicitLanguage) {
         nsAutoCString langString;
         style->language->ToUTF8String(langString);
         grLang = GetGraphiteTagForLang(langString);

gfx/thebes/gfxHarfBuzzShaper.cpp

@@ -1228,11 +1228,13 @@ gfxHarfBuzzShaper::ShapeText(gfxContext      *aContext,
         language = hb_ot_tag_to_language(style->languageOverride);
     } else if (entry->mLanguageOverride) {
         language = hb_ot_tag_to_language(entry->mLanguageOverride);
-    } else {
+    } else if (style->explicitLanguage) {
         nsCString langString;
         style->language->ToUTF8String(langString);
         language =
             hb_language_from_string(langString.get(), langString.Length());
+    } else {
+        language = hb_ot_tag_to_language(HB_OT_TAG_DEFAULT_LANGUAGE);
     }
     hb_buffer_set_language(buffer, language);