Bug 107833

Summary: REGRESSION (r135628-135632): Double box shadow failure to render
Product: WebKit Reporter: Nathan Crank <me>
Component: CSSAssignee: Justin Novosad <junov>
Status: RESOLVED FIXED    
Severity: Normal CC: bdakin, dglazkov, eric, fmalita, jchaffraix, junov, menard, ojan.autocc, senorblanco, simon.fraser, webkit.review.bot
Priority: P1 Keywords: InRadar, Regression
Version: 528+ (Nightly build)   
Hardware: All   
OS: All   
Attachments:
Description Flags
Patch
none
Patch for landing
none
Patch for landing
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Patch for landing none

Description Nathan Crank 2013-01-24 08:45:30 PST
I have found a strange bug in the nightlies of webkit and canary.

If you check out http://codepen.io/nathancrank/pen/JCFyk in release Safari or Chrome, you'll see the second box shadow render on the submit input. If you load it in nightlies it will only render the first shadow, unless you add a third shadow declaration to it.
Comment 1 Alexey Proskuryakov 2013-01-25 10:27:22 PST
Two potentially related revisions in the range:

<http://trac.webkit.org/changeset/135629> Adding occlusion detection to reduce overdraw in RenderBox background rendering

<http://trac.webkit.org/changeset/135632> [CSS3 Backgrounds and Borders] Implement new CSS3 background-position parsing.
Comment 2 Alexey Proskuryakov 2013-01-25 10:27:44 PST
<rdar://problem/13087228>
Comment 3 Justin Novosad 2013-01-28 08:39:02 PST
(In reply to comment #1)
Just verified that the regression was in fact caused by http://trac.webkit.org/changeset/135629
Comment 4 Justin Novosad 2013-01-28 14:34:53 PST
Created attachment 185066 [details]
Patch
Comment 5 Simon Fraser (smfr) 2013-01-28 14:45:21 PST
Comment on attachment 185066 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=185066&action=review

> Source/WebCore/ChangeLog:8
> +        Reviewed by NOBODY (OOPS!).
> +
> +        Test: fast/backgrounds/gradient-background-shadow.html

Please explain the bug and how you fixed it, identifying the revision that caused it.

> Source/WebCore/ChangeLog:12
> +        Changeing occlusion culling test to never cull background color

Changing
Comment 6 WebKit Review Bot 2013-01-29 00:53:44 PST
Comment on attachment 185066 [details]
Patch

Attachment 185066 [details] did not pass chromium-ews (chromium-xvfb):
Output: http://queues.webkit.org/results/16201044

New failing tests:
fast/backgrounds/gradient-background-shadow.html
Comment 7 Justin Novosad 2013-01-29 07:27:42 PST
Created attachment 185243 [details]
Patch for landing
Comment 8 Justin Novosad 2013-01-29 07:30:40 PST
Created attachment 185245 [details]
Patch for landing
Comment 9 WebKit Review Bot 2013-01-29 08:21:19 PST
Comment on attachment 185245 [details]
Patch for landing

Rejecting attachment 185245 [details] from commit-queue.

New failing tests:
fast/backgrounds/gradient-background-shadow.html
Full output: http://queues.webkit.org/results/16195168
Comment 10 Justin Novosad 2013-01-29 11:16:31 PST
(In reply to comment #9)
> (From update of attachment 185245 [details])
> Rejecting attachment 185245 [details] from commit-queue.
> 
> New failing tests:
> fast/backgrounds/gradient-background-shadow.html
> Full output: http://queues.webkit.org/results/16195168

The failure in the new test looks like it is caused by a regression that must have landed since yesterday.  Looks like there are LSB discrepancies in gradient rendering.  This is probably limited to the skia port.

fmalita, you know anything about this?
Comment 11 Justin Novosad 2013-01-29 11:38:33 PST
Geez, looks like I was using a stale checkout.  Related regressions were added to test expectations 3 weeks ago with: http://trac.webkit.org/changeset/139512
We should fix skia gradients so that we can re-enable some ref tests.
Comment 12 Justin Novosad 2013-01-29 12:13:55 PST
The nature of the problem with skia gradients is understood and documented here: https://code.google.com/p/chromium/issues/detail?id=169602

Until that is fixed, I'll just put the new test in chromium TestExpectations. It passes on other WK ports.
Comment 13 Justin Novosad 2013-01-29 12:20:29 PST
Created attachment 185282 [details]
Patch for landing
Comment 14 WebKit Review Bot 2013-01-29 13:33:39 PST
Comment on attachment 185282 [details]
Patch for landing

Clearing flags on attachment: 185282

Committed r141160: <http://trac.webkit.org/changeset/141160>
Comment 15 WebKit Review Bot 2013-01-29 13:33:44 PST
All reviewed patches have been landed.  Closing bug.