Bug 56585 - [chromium] Turn off accelerated compositing for RTL style pages.
Summary: [chromium] Turn off accelerated compositing for RTL style pages.
Status: RESOLVED FIXED
Alias: None
Product: WebKit
Classification: Unclassified
Component: WebCore Misc. (show other bugs)
Version: 528+ (Nightly build)
Hardware: All All
: P2 Normal
Assignee: Adrienne Walker
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2011-03-17 13:29 PDT by Adrienne Walker
Modified: 2011-03-17 15:17 PDT (History)
6 users (show)

See Also:


Attachments
Patch (3.01 KB, patch)
2011-03-17 13:37 PDT, Adrienne Walker
jamesr: review+
Details | Formatted Diff | Diff

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Description Adrienne Walker 2011-03-17 13:29:27 PDT
[chromium] Turn off accelerated compositing for RTL style pages.
Comment 1 Adrienne Walker 2011-03-17 13:36:10 PDT
RTL style is not properly supported in the compositor, so turn it off until a proper fix has been implemented.
Comment 2 Adrienne Walker 2011-03-17 13:37:16 PDT
Created attachment 86087 [details]
Patch
Comment 3 Adrienne Walker 2011-03-17 13:42:49 PDT
I tested this both on an initial page as well as by switching the style dynamically from RTL to LTR and back.  doLayout() seemed like the best place to do this dynamic check in.  Backporting this to m11 fixes the problem there too.
Comment 4 Adrienne Walker 2011-03-17 14:04:13 PDT
Nat asks the question: "What about iframes?"

Answer: an ltr page with an iframe that references an rtl page desn't appear to render properly even with this fix.  Accelerated compositing doesn't get turned off because the page is still ltr even though the iframe is rtl.  However, the compositor doesn't have the same indexing problems because the page is still ltr.

I guess I could try to detect if any element on the page was RTL and then disable accelerated compositing, but that seems a bit much.  This is intended to be a temporary fix, anyway.
Comment 5 Simon Fraser (smfr) 2011-03-17 14:14:28 PDT
> RTL style is not properly supported in the compositor
What bugs cover that?
Comment 6 Adrienne Walker 2011-03-17 14:21:02 PDT
(In reply to comment #5)
> > RTL style is not properly supported in the compositor
> What bugs cover that?

This was just discovered yesterday and I was trying to fight the fire first with this bug.  I filed a bug here to fix it properly: https://bugs.webkit.org/show_bug.cgi?id=56591

For what it's worth, this is a Chromium-only issue.
Comment 7 James Robinson 2011-03-17 14:43:56 PDT
Comment on attachment 86087 [details]
Patch

R=me. this is unfortunate but I think it's better to force software for these pages instead of rendering incorrectly.
Comment 8 Adrienne Walker 2011-03-17 15:17:29 PDT
Committed r81395: <http://trac.webkit.org/changeset/81395>