Bug 41137 – [Qt] QtWebKit -webkit-transform:translate3d fails on big DIV elements

• Status: RESOLVED
• Resolution: WORKSFORME
• Component: Layout and Rendering

[Jonni Rainisto]

Created attachment 59623 [details]
scrolling-testcase

Following scrolling-testcase.html file fails in Harmattan QtWebkit (red div turns black/disapears), and works on other platforms. Maybe QtWebKit OpenGL backend releated bug?

[Diego Gonzalez]

Cannot reproduce this bug. Please check if it is still reproducible for you. If so try to reproduce it in a open platform.

[Jonni Rainisto]

I can still reproduce this in Harmattan week31 release, so its still valid. Seems to be releated to QTWebKit opengl es2 backed, since div stays red if I do --graphicssystem=raster -software. Cannot reproduce on open platform (as I dont have any open hw which has gles2 backend).

[Jonni Rainisto]

I can still reproduce this in Harmattan 38-8 QtWebKit using webwidgetrunner (red div disapears when you try to scroll the screen.

[Suresh Voruganti]

Is this still reproducible? Can you give Meego Bugzilla ID?

[Jonni Rainisto]

Yes, its still reproducible in 43-6. I created now also PMO bug in https://projects.maemo.org/bugzilla/show_bug.cgi?id=200690

[Simon Hausmann]

Could this be a problem in the OpenGL paint engine?

[Benjamin Poulain]

I think MAX_TEXTURE_SIZE is 2048 in this case. Textures bigger than that just fail.

This could be worked around by adding tiling for texture, either in WebKit or (better) in the graphics system.

I am tempted to just ignore that for the graphics view implementation and  do a proper fix for the texture mapper. How important is the bug?

[Simon Hausmann]

(In reply to comment #7)
> How important is the bug?

It originates from a Maemo 6 bug (41137), triggered by the Qt Web Runtime.

[Noam Rosenthal]

See https://bugs.webkit.org/show_bug.cgi?id=39691, I think it fixes it, though the patch needs to be re-applied etc.

[Ademar Reis]

Please confirm if bug 39691 fixes it so that I can backport/cherry-pick the fix into qtwebkit-2.1

[Suresh Voruganti]

I think we cannot test with out the fix of 39691 integrated to Qtwebkit 2.1

Let me know if we can test with out the fix being picked to 2.1?

[Ademar Reis]

Created attachment 72856 [details]
patch enabling tiling on qtwebkit-2.1

Patch backported to qtwebkit-2.1. Please test, if it really solves the problem I'll push it into the official branch.

[Jonni Rainisto]

applied the patch to harmattan 43-6, and tested it, but bug still appears. So this patch does not help.(In reply to comment #12)
> Created an attachment (id=72856) [details]
> patch enabling tiling on qtwebkit-2.1
> 
> Patch backported to qtwebkit-2.1. Please test, if it really solves the problem I'll push it into the official branch.

applied the patch to harmattan 43-6 qtwebkit sources, and tested it, but bug still appears. So this patch does not seem to help.

[Noam Rosenthal]

Can we work around this for now (e.g. by using smaller layers in HTML) and postpone actual fix to 2.2?