|Summary:||[wk2] WebKitTestRunner's window snapshots are blank with tiled drawing|
|Product:||WebKit||Reporter:||Tim Horton <thorton>|
|Component:||Tools / Tests||Assignee:||Tim Horton <thorton>|
|Severity:||Normal||CC:||andersca, ap, commit-queue, sam, simon.fraser, webkit-bug-importer|
|Version:||528+ (Nightly build)|
|Bug Depends on:||122035, 122152, 122176|
Description Tim Horton 2013-09-26 22:34:03 PDT
WebKitTestRunner's window snapshots are pure white no matter what's on screen when they're taken, if tiled drawing is on (possibly any time remote layer hosting is occurring?) and WKTR's window has a buffered backing store. This doesn't show up in ref tests because it's broken in both the ref and the actual result; pixel tests make it the most clear (but we don't have any tiled-drawing pixel tests, nor do we run the other ones very often). I've added a mismatch test to ensure this doesn't happen again, as I'm going to switch WKTR to tiled drawing 24/7 very soon, and it would be really bad if we lost all ref image coverage :| Conveniently, we're really mostly interested in testing unbuffered windows anyway.
Comment 2 Tim Horton 2013-09-26 22:52:47 PDT
Created attachment 212789 [details] preliminary I'm seeing some tests that use the non-tiled path fail with this change, so it might require more investigation.
Comment 3 Tim Horton 2013-09-27 13:21:44 PDT
We can't override the window resolution with an unbuffered window, so this breaks the workaround we use to make tests work on Retina machines. I'll try to come up with something else.