Bug 144723 - REGRESSION (r164449): Subpixel rendering: http://www.apple.com/iphone-6/ "Faster wireless." image displays vertical black line on 1x displays at specific window width.
Summary: REGRESSION (r164449): Subpixel rendering: http://www.apple.com/iphone-6/ "Fas...
Status: RESOLVED FIXED
Alias: None
Product: WebKit
Classification: Unclassified
Component: Layout and Rendering (show other bugs)
Version: 528+ (Nightly build)
Hardware: Unspecified Unspecified
: P2 Normal
Assignee: zalan
URL:
Keywords: InRadar
Depends on:
Blocks:
 
Reported: 2015-05-06 18:40 PDT by zalan
Modified: 2015-05-07 15:04 PDT (History)
10 users (show)

See Also:


Attachments
Patch (7.96 KB, patch)
2015-05-06 20:20 PDT, zalan
no flags Details | Formatted Diff | Diff
Archive of layout-test-results from ews105 for mac-mavericks-wk2 (568.63 KB, application/zip)
2015-05-06 20:57 PDT, Build Bot
no flags Details
Archive of layout-test-results from ews101 for mac-mavericks (530.15 KB, application/zip)
2015-05-06 21:09 PDT, Build Bot
no flags Details
Patch (8.88 KB, patch)
2015-05-06 21:10 PDT, zalan
no flags Details | Formatted Diff | Diff
Patch (10.28 KB, patch)
2015-05-07 11:58 PDT, zalan
no flags Details | Formatted Diff | Diff

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Description zalan 2015-05-06 18:40:50 PDT
1. Launch Safari on a 1x display
2. Navigate to http://www.apple.com/iphone-6/
3. Scroll down to "Faster wireless." image and adjust window width between 1,115 and 1,295 pixels
Comment 1 zalan 2015-05-06 18:41:12 PDT
rdar://problem/18307094
Comment 2 zalan 2015-05-06 20:20:44 PDT
Created attachment 252560 [details]
Patch
Comment 3 Build Bot 2015-05-06 20:57:36 PDT
Comment on attachment 252560 [details]
Patch

Attachment 252560 [details] did not pass mac-wk2-ews (mac-wk2):
Output: http://webkit-queues.appspot.com/results/5888337206312960

New failing tests:
compositing/layer-creation/overlap-animation-container.html
Comment 4 Build Bot 2015-05-06 20:57:39 PDT
Created attachment 252561 [details]
Archive of layout-test-results from ews105 for mac-mavericks-wk2

The attached test failures were seen while running run-webkit-tests on the mac-wk2-ews.
Bot: ews105  Port: mac-mavericks-wk2  Platform: Mac OS X 10.9.5
Comment 5 Simon Fraser (smfr) 2015-05-06 21:04:15 PDT
Comment on attachment 252560 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=252560&action=review

> Source/WebCore/rendering/RenderLayerBacking.cpp:728
> +        ancestorCompositingBounds = LayoutRect(encloseRectToDevicePixels(compAncestor->backing()->compositedBounds(), deviceScaleFactor));

Should we just store the encloseRectToDevicePixels rect on the backing?

Also, doesn't this also break our rule that you can only do enclosing computations on things that are in absolute coordinates?

> LayoutTests/ChangeLog:16
> +        * compositing/ancestor-compositing-layer-is-on-subpixel-position-expected.html: Added.
> +        * compositing/ancestor-compositing-layer-is-on-subpixel-position.html: Added.

Do ref tests actually pick up the difference? I would have thought a layer tree dump would be more reliable.
Comment 6 Build Bot 2015-05-06 21:09:19 PDT
Comment on attachment 252560 [details]
Patch

Attachment 252560 [details] did not pass mac-ews (mac):
Output: http://webkit-queues.appspot.com/results/4598034541314048

New failing tests:
compositing/layer-creation/overlap-animation-container.html
Comment 7 Build Bot 2015-05-06 21:09:23 PDT
Created attachment 252563 [details]
Archive of layout-test-results from ews101 for mac-mavericks

The attached test failures were seen while running run-webkit-tests on the mac-ews.
Bot: ews101  Port: mac-mavericks  Platform: Mac OS X 10.9.5
Comment 8 zalan 2015-05-06 21:10:49 PDT
Created attachment 252564 [details]
Patch
Comment 9 zalan 2015-05-06 21:11:38 PDT
(In reply to comment #7)
> Created attachment 252563 [details]
> Archive of layout-test-results from ews101 for mac-mavericks
> 
> The attached test failures were seen while running run-webkit-tests on the
> mac-ews.
> Bot: ews101  Port: mac-mavericks  Platform: Mac OS X 10.9.5
This is a progression.
Comment 10 zalan 2015-05-07 11:58:46 PDT
Created attachment 252604 [details]
Patch
Comment 11 WebKit Commit Bot 2015-05-07 15:04:35 PDT
Comment on attachment 252604 [details]
Patch

Clearing flags on attachment: 252604

Committed r183950: <http://trac.webkit.org/changeset/183950>
Comment 12 WebKit Commit Bot 2015-05-07 15:04:42 PDT
All reviewed patches have been landed.  Closing bug.