SkFontStyleSet_DirectWrite::getStyle to properly handle NULL out params.

src/ports/SkFontHost_win_dw.cpp

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkTypes.h"
 #undef GetGlyphIndices
 
@@ skipping 1814 matching lines @@
     SkTScopedComPtr<IDWriteFontFace> fontFace;
     HRNM(font->CreateFontFace(&fontFace), "Could not create font face.");
 
     return fFontMgr->createTypefaceFromDWriteFont(fontFace.get(), font.get(), fFontFamily.get());
 }
 
 void SkFontStyleSet_DirectWrite::getStyle(int index, SkFontStyle* fs, SkString* styleName) {
     SkTScopedComPtr<IDWriteFont> font;
     HRVM(fFontFamily->GetFont(index, &font), "Could not get font.");
 
-    SkFontStyle::Slant slant;
-    switch (font->GetStyle()) {
-    case DWRITE_FONT_STYLE_NORMAL:
-        slant = SkFontStyle::kUpright_Slant;
-        break;
-    case DWRITE_FONT_STYLE_OBLIQUE:
-    case DWRITE_FONT_STYLE_ITALIC:
-        slant = SkFontStyle::kItalic_Slant;
-        break;
-    default:
-        SkASSERT(false);
+    if (fs) {
+        SkFontStyle::Slant slant;
+        switch (font->GetStyle()) {
+        case DWRITE_FONT_STYLE_NORMAL:
+            slant = SkFontStyle::kUpright_Slant;
+            break;
+        case DWRITE_FONT_STYLE_OBLIQUE:
+        case DWRITE_FONT_STYLE_ITALIC:
+            slant = SkFontStyle::kItalic_Slant;
+            break;
+        default:
+            SkASSERT(false);
+        }
+
+        int weight = font->GetWeight();
+        int width = font->GetStretch();
+
+        *fs = SkFontStyle(weight, width, slant);
     }
 
-    int weight = font->GetWeight();
-    int width = font->GetStretch();
-
-    *fs = SkFontStyle(weight, width, slant);
-
-    SkTScopedComPtr<IDWriteLocalizedStrings> faceNames;
-    if (SUCCEEDED(font->GetFaceNames(&faceNames))) {
-        get_locale_string(faceNames.get(), fFontMgr->fLocaleName.get(), styleName);
+    if (styleName) {
+        SkTScopedComPtr<IDWriteLocalizedStrings> faceNames;
+        if (SUCCEEDED(font->GetFaceNames(&faceNames))) {
+            get_locale_string(faceNames.get(), fFontMgr->fLocaleName.get(), styleName);
+        }
     }
 }
 
 SkTypeface* SkFontStyleSet_DirectWrite::matchStyle(const SkFontStyle& pattern) {
     DWRITE_FONT_STYLE slant;
     switch (pattern.slant()) {
     case SkFontStyle::kUpright_Slant:
         slant = DWRITE_FONT_STYLE_NORMAL;
         break;
     case SkFontStyle::kItalic_Slant:
@@ skipping 56 matching lines @@
         SK_TRACEHR(hr, "Could not get GetUserDefaultLocaleName.");
     } else {
         localeNameLen = getUserDefaultLocaleNameProc(localeNameStorage, LOCALE_NAME_MAX_LENGTH);
         if (localeNameLen) {
             localeName = localeNameStorage;
         };
     }
 
     return SkNEW_ARGS(SkFontMgr_DirectWrite, (sysFontCollection.get(), localeName, localeNameLen));
 }