Image filters: fix the zero-sigma fast path in SkBlurImageFilter.

src/effects/SkBlurImageFilter.cpp

 /*
  * Copyright 2011 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkBitmap.h"
 #include "SkBlurImageFilter.h"
 #include "SkColorPriv.h"
@@ skipping 86 matching lines @@
     int kernelSizeX, kernelSizeX3, lowOffsetX, highOffsetX;
     int kernelSizeY, kernelSizeY3, lowOffsetY, highOffsetY;
     getBox3Params(sigma.x(), &kernelSizeX, &kernelSizeX3, &lowOffsetX, &highOffsetX);
     getBox3Params(sigma.y(), &kernelSizeY, &kernelSizeY3, &lowOffsetY, &highOffsetY);
 
     if (kernelSizeX < 0 || kernelSizeY < 0) {
         return false;
     }
 
     if (kernelSizeX == 0 && kernelSizeY == 0) {
-        src.extractSubset(dst, srcBounds);
+        src.extractSubset(dst, srcBounds.makeOffset(-srcOffset.x(), -srcOffset.y()));
         offset->fX = srcBounds.x();
         offset->fY = srcBounds.y();
         return true;
     }
 
     SkAutoLockPixels alp(src);
     if (!src.getPixels()) {
         return false;
     }
 
@@ skipping 93 matching lines @@
     srcBounds.offset(srcOffset);
     SkIRect dstBounds;
     if (!this->applyCropRect(this->mapContext(ctx), srcBounds, &dstBounds)) {
         return false;
     }
     if (!srcBounds.intersect(dstBounds)) {
         return false;
     }
     SkVector sigma = map_sigma(fSigma, ctx.ctm());
     if (sigma.x() == 0 && sigma.y() == 0) {
-        input.extractSubset(result, srcBounds);
+        input.extractSubset(result, srcBounds.makeOffset(-srcOffset.x(), -srcOffset.y()));
         offset->fX = srcBounds.x();
         offset->fY = srcBounds.y();
         return true;
     }
     offset->fX = dstBounds.fLeft;
     offset->fY = dstBounds.fTop;
     srcBounds.offset(-srcOffset);
     dstBounds.offset(-srcOffset);
     SkRect srcBoundsF(SkRect::Make(srcBounds));
     GrTexture* inputTexture = input.getTexture();
@@ skipping 20 matching lines @@
     str->appendf("SkBlurImageFilter: (");
     str->appendf("sigma: (%f, %f) input (", fSigma.fWidth, fSigma.fHeight);
 
     if (this->getInput(0)) {
         this->getInput(0)->toString(str);
     }
 
     str->append("))");
 }
 #endif