This is unlikely to cause real problems since cases where we use mSamplingRect shouldn't normally deal with very large images. But CreatePartialBitmapForSurface doesn't play nicely with SurfacePattern::mSamplingRect. This means for border-image where the image is larger than 8192 pixels in some direction we might have a bug. I don't think this is high priority but I wanted to have this on file in case someone does run into this.

Is this what you had in mind?

Looks like this may be high priority, found two duplicates of it already.

[Tracking Requested - why for this release]:

Comment on attachment 8498543 [details] [diff] [review] Do partial uploads when we have a sampling rect Review of attachment 8498543 [details] [diff] [review]: ----------------------------------------------------------------- Yup, this should do it, we'll need something similar for D2D 1.1. Again, no hurry, but eventually it's probably better if we sort it out. It's probably going to be a little annoying to test. ::: gfx/2d/DrawTargetD2D.cpp @@ +2378,5 @@ > MOZ_ASSERT("Invalid sampling rect size!"); > return nullptr; > } > > + dt->CopySurface(source, samplingRect, IntPoint()) nit: You'll need to re-add that ; you removed :P @@ +2418,5 @@ > + if (sourceRect.IsEmpty()) { > + sourceRect = IntRect(0, 0, source->GetSize().width, source->GetSize().height); > + } > + > + bitmap = CreatePartialBitmapForSurface(dataSurf, mTransform, mSize, pat->mExtendMode, mat, mRT, &sourceRect); nit: might as well fix the whitespace while you're in this line :)