Prevent MipMaps from crashing.

git-svn-id: http://skia.googlecode.com/svn/trunk@4753 2bbb7eff-a529-9590-31e7-b0007b416f81

1 files changed, 2 insertions, 0 deletions

diff --git a/src/core/SkBitmap.cpp b/src/core/SkBitmap.cpp
index 2df5e56e5a..687cf7a000 100644
--- a/src/core/SkBitmap.cpp
+++ b/src/core/SkBitmap.cpp
@@ -1161,11 +1161,13 @@ void SkBitmap::buildMipMap(bool forceRebuild) {
         dstBM.setConfig(config, width, height, rowBytes);
         dstBM.setPixels(addr);
 
+        srcBM.lockPixels();
         for (int y = 0; y < height; y++) {
             for (int x = 0; x < width; x++) {
                 proc(&dstBM, x, y, srcBM);
             }
         }
+        srcBM.unlockPixels();
 
         srcBM = dstBM;
         addr += height * rowBytes;