Fix potential crash when shaping Hebrew with bold

- make code more resilient
- make correct initialization of gHebrewRegularTypeface

Change-Id: I97e98d36b830ad35979184c1459e8c8503eb3d28

3 files changed, 19 insertions, 15 deletions

diff --git a/core/jni/android/graphics/HarfbuzzSkia.cpp b/core/jni/android/graphics/HarfbuzzSkia.cpp
index 92c743f..e02070d 100644
--- a/core/jni/android/graphics/HarfbuzzSkia.cpp
+++ b/core/jni/android/graphics/HarfbuzzSkia.cpp
@@ -24,6 +24,8 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
+#define LOG_TAG "HarfbuzzSkia"
+
 #include "HarfbuzzSkia.h"
 
 #include "SkFontHost.h"
@@ -214,6 +216,10 @@ HB_Error harfbuzzSkiaGetTable(void* voidface, const HB_Tag tag, HB_Byte* buffer,
     FontData* data = reinterpret_cast<FontData*>(voidface);
     SkTypeface* typeface = data->typeFace;
 
+    if (!typeface) {
+        LOGD("Typeface cannot be null");
+        return HB_Err_Invalid_Argument;
+    }
     const size_t tableSize = SkFontHost::GetTableSize(typeface->uniqueID(), tag);
     if (!tableSize)
         return HB_Err_Invalid_Argument;
diff --git a/core/jni/android/graphics/TextLayoutCache.cpp b/core/jni/android/graphics/TextLayoutCache.cpp
index 104c83d..bfd2061 100644
--- a/core/jni/android/graphics/TextLayoutCache.cpp
+++ b/core/jni/android/graphics/TextLayoutCache.cpp
@@ -415,10 +415,7 @@ unsigned TextLayoutCacheValue::shapeFontRun(HB_ShaperItem& shaperItem, SkPaint*
     FontData* data = reinterpret_cast<FontData*>(shaperItem.font->userData);
     switch(shaperItem.item.script) {
         case HB_Script_Arabic:
-            if (!gArabicTypeface) {
-                gArabicTypeface = SkTypeface::CreateFromFile(TYPEFACE_ARABIC);
-            }
-            data->typeFace = gArabicTypeface;
+            data->typeFace = getCachedTypeface(gArabicTypeface, TYPEFACE_ARABIC);
 #if DEBUG_GLYPHS
             LOGD("Using Arabic Typeface");
 #endif
@@ -430,29 +427,21 @@ unsigned TextLayoutCacheValue::shapeFontRun(HB_ShaperItem& shaperItem, SkPaint*
                     case SkTypeface::kNormal:
                     case SkTypeface::kItalic:
                     default:
-                        if (!gHebrewRegularTypeface) {
-                            gHebrewRegularTypeface = SkTypeface::CreateFromFile(
-                                    TYPE_FACE_HEBREW_REGULAR);
-                        }
-                        data->typeFace = gHebrewRegularTypeface;
+                        data->typeFace = getCachedTypeface(gHebrewRegularTypeface, TYPE_FACE_HEBREW_REGULAR);
 #if DEBUG_GLYPHS
                         LOGD("Using Hebrew Regular/Italic Typeface");
 #endif
                         break;
                     case SkTypeface::kBold:
                     case SkTypeface::kBoldItalic:
-                        if (!gHebrewBoldTypeface) {
-                            gHebrewBoldTypeface = SkTypeface::CreateFromFile(
-                                    TYPE_FACE_HEBREW_BOLD);
-                        }
-                        data->typeFace = gHebrewBoldTypeface;
+                        data->typeFace = getCachedTypeface(gHebrewBoldTypeface, TYPE_FACE_HEBREW_BOLD);
 #if DEBUG_GLYPHS
                         LOGD("Using Hebrew Bold/BoldItalic Typeface");
 #endif
                         break;
                 }
             } else {
-                data->typeFace = gHebrewRegularTypeface;
+                data->typeFace = getCachedTypeface(gHebrewRegularTypeface, TYPE_FACE_HEBREW_REGULAR);
 #if DEBUG_GLYPHS
                         LOGD("Using Hebrew Regular Typeface");
 #endif
@@ -492,6 +481,13 @@ unsigned TextLayoutCacheValue::shapeFontRun(HB_ShaperItem& shaperItem, SkPaint*
     return result;
 }
 
+SkTypeface* TextLayoutCacheValue::getCachedTypeface(SkTypeface* typeface, const char path[]) {
+    if (!typeface) {
+        typeface = SkTypeface::CreateFromFile(path);
+    }
+    return typeface;
+}
+
 void TextLayoutCacheValue::computeValuesWithHarfbuzz(SkPaint* paint, const UChar* chars,
         size_t start, size_t count, size_t contextCount, int dirFlags,
         Vector<jfloat>* const outAdvances, jfloat* outTotalAdvance,
diff --git a/core/jni/android/graphics/TextLayoutCache.h b/core/jni/android/graphics/TextLayoutCache.h
index a5d8eb7..3b612ff 100644
--- a/core/jni/android/graphics/TextLayoutCache.h
+++ b/core/jni/android/graphics/TextLayoutCache.h
@@ -174,6 +174,8 @@ private:
     static unsigned shapeFontRun(HB_ShaperItem& shaperItem, SkPaint* paint,
             size_t count, bool isRTL);
 
+    static SkTypeface* getCachedTypeface(SkTypeface* typeface, const char path[]);
+
     static void deleteGlyphArrays(HB_ShaperItem& shaperItem);
 
     static void createGlyphArrays(HB_ShaperItem& shaperItem, int size);