Handle shader construction failures gracefully

third_party/WebKit/Source/core/svg/graphics/SVGImage.cpp

 /*
  * Copyright (C) 2006 Eric Seidel <eric@webkit.org>
  * Copyright (C) 2008, 2009 Apple Inc. All rights reserved.
  * Copyright (C) Research In Motion Limited 2011. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
@@ skipping 302 matching lines @@
   sk_sp<PaintRecord> tilePicture = patternPicture.endRecording();
 
   SkMatrix patternTransform;
   patternTransform.setTranslate(phase.x() + spacedTile.x(),
                                 phase.y() + spacedTile.y());
 
   PaintFlags paint;
   paint.setShader(MakePaintShaderRecord(tilePicture, SkShader::kRepeat_TileMode,
                                         SkShader::kRepeat_TileMode,
                                         &patternTransform, nullptr));
+  // If the shader could not be instantiated (e.g. non-invertible matrix),
+  // draw transparent.
+  // Note: we can't simply bail, because of arbitrary blend mode.
+  if (!paint.getShader())
+    paint.setColor(SK_ColorTRANSPARENT);
+
   paint.setBlendMode(compositeOp);
   paint.setColorFilter(sk_ref_sp(context.getColorFilter()));
   context.drawRect(dstRect, paint);
 }
 
 sk_sp<SkImage> SVGImage::imageForCurrentFrameForContainer(
     const KURL& url,
     const IntSize& containerSize) {
   if (!m_page)
     return nullptr;
@@ skipping 315 matching lines @@
   }
 
   return m_page ? SizeAvailable : SizeUnavailable;
 }
 
 String SVGImage::filenameExtension() const {
   return "svg";
 }
 
 }  // namespace blink