[webkit-reviews] review requested: [Bug 46812] [Qt] Crash if an scene with accelerated compositing layout during the paint event : [Attachment 69237] Patch

[bugzilla-daemon at webkit.org]

Benjamin Poulain <benjamin.poulain at nokia.com> has asked  for review:
Bug 46812: [Qt] Crash if an scene with accelerated compositing layout during
the paint event
https://bugs.webkit.org/show_bug.cgi?id=46812

Attachment 69237: Patch
https://bugs.webkit.org/attachment.cgi?id=69237&action=review

------- Additional Comments from Benjamin Poulain <benjamin.poulain at nokia.com>
We have two options:
-keep the overlay around but hide it
-delete the overlay with deleteLater.

I prefer deleting the overlay because:
1) hiding it will not solve the problem that the current frame is gonna be
rendered incorrectly
2) QGraphicsItem::setVisible() does not define explicitely what happen to the
cached data. A clever algorithm might decide to keep the cached pixmap around
and keep track of the updates.
3) accelerated compositing might not be used ever after this page, not point at
keeping the memory around

I leave the commit queue blank for now. I hope No'am will have time to look at
this patch.