To avoid QPainter moaning on the console. Basically, we need to check if (painter->paintEngine()->hasFeature(QPaintEngine::PorterDuff)). Note that this isn't relevant when painting on a QImage.
Created attachment 76657 [details] Proposed patch
Comment on attachment 76657 [details] Proposed patch LGTM.
The commit-queue encountered the following flaky tests while processing attachment 76657 [details]: fast/canvas/webgl/tex-sub-image-2d.html bug 51153 (authors: abarth@webkit.org, kbr@google.com, and zmo@google.com) accessibility/media-element.html bug 51154 (author: eric.carlson@apple.com) The commit-queue is continuing to process your patch.
Comment on attachment 76657 [details] Proposed patch Clearing flags on attachment: 76657 Committed r74165: <http://trac.webkit.org/changeset/74165>
All reviewed patches have been landed. Closing bug.