It doesn't really make sense for createExclusionShape to return null. It would be more with WebKit style to ensure that it need gets passed a null shape and have it ASSERT that the shape is not null. See comments on bug 100398 for the genesis of this bug.
Created attachment 174557 [details]
ExclusionShape::createExclusionShape now ASSERTs that its basicShape argument isn't null, since the caller is expected to ensure as much.
Comment on attachment 174557 [details]
Attachment 174557 [details] did not pass chromium-ews (chromium-xvfb):
New failing tests:
Created attachment 174708 [details]
The probability that my small change to createExclusionShape() impacted a WebGL test seems extremely small so I've sync'd with the latest repository and uploaded a new version of the same patch.
Comment on attachment 174708 [details]
Clearing flags on attachment: 174708
Committed r135166: <http://trac.webkit.org/changeset/135166>
All reviewed patches have been landed. Closing bug.