$OpenBSD$

index 6b7e833..c78e562 100644
--- image/src/imgFrame.cpp.orig	Fri Feb 20 15:40:37 2015
+++ image/src/imgFrame.cpp	Fri Feb 20 15:40:37 2015
@@ -232,6 +232,11 @@ nsresult imgFrame::Init(int32_t aX, int32_t aY, int32_t aWidth, int32_t aHeight,
       if (!mVBuf) {
         return NS_ERROR_OUT_OF_MEMORY;
       }
+      if (mVBuf->OnHeap()) {
+        long stride = gfxImageSurface::ComputeStride(mSize, mFormat);
+        VolatileBufferPtr<uint8_t> ptr(mVBuf);
+        memset(ptr, 0, stride * mSize.height);
+      }
       mImageSurface = LockedImageSurface::CreateSurface(mVBuf, mSize, mFormat);
     }