Merge 96151 - Rapidly refreshing a feMorphology[erode] with r=0 can sometimes cause display corru...

Source/WebCore/platform/graphics/filters/FEMorphology.cpp

 /*
  * Copyright (C) 2004, 2005, 2006, 2007 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) 2004, 2005 Rob Buis <buis@kde.org>
  * Copyright (C) 2005 Eric Seidel <eric@webkit.org>
  * Copyright (C) 2009 Dirk Schulze <krit@webkit.org>
  * Copyright (C) Research In Motion Limited 2010. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
@@ skipping 189 matching lines @@
     FilterEffect* in = inputEffect(0);
     in->apply();
     if (!in->hasResult())
         return;
 
     ByteArray* dstPixelArray = createPremultipliedImageResult();
     if (!dstPixelArray)
         return;
 
     setIsAlphaImage(in->isAlphaImage());
-    if (m_radiusX <= 0 || m_radiusY <= 0)
+    if (m_radiusX <= 0 || m_radiusY <= 0) {
+        dstPixelArray->clear();
         return;
+    }
 
     Filter* filter = this->filter();
     int radiusX = static_cast<int>(floorf(filter->applyHorizontalScale(m_radiusX)));
     int radiusY = static_cast<int>(floorf(filter->applyVerticalScale(m_radiusY)));
 
     IntRect effectDrawingRect = requestedRegionOfInputImageData(in->absolutePaintRect());
     RefPtr<ByteArray> srcPixelArray = in->asPremultipliedImage(effectDrawingRect);
 
     PaintingData paintingData;
     paintingData.srcPixelArray = srcPixelArray.get();
@@ skipping 33 matching lines @@
     FilterEffect::externalRepresentation(ts);
     ts << " operator=\"" << morphologyOperator() << "\" "
        << "radius=\"" << radiusX() << ", " << radiusY() << "\"]\n";
     inputEffect(0)->externalRepresentation(ts, indent + 1);
     return ts;
 }
 
 } // namespace WebCore
 
 #endif // ENABLE(FILTERS)