Bug 252925

Summary: REGRESSION (STP 164): new failure in css/css-backgrounds/parsing/background-shorthand-serialization.html
Product: WebKit Reporter: Antoine Quint <graouts>
Component: CSSAssignee: Darin Adler <darin>
Status: RESOLVED FIXED    
Severity: Normal CC: darin, webkit-bug-importer
Priority: P2 Keywords: InRadar
Version: WebKit Nightly Build   
Hardware: Unspecified   
OS: Unspecified   
See Also: https://github.com/w3c/csswg-drafts/issues/8496
https://bugs.webkit.org/show_bug.cgi?id=251838

Description Antoine Quint 2023-02-24 13:09:32 PST 
The last subtest of css/css-backgrounds/parsing/background-shorthand-serialization.html is failing in STP 164 when it used to pass in STP 163:

https://wpt.fyi/results/css/css-backgrounds/parsing/background-shorthand-serialization.html?label=master&label=experimental&product=safari-163%20preview&product=safari-164%20preview&view=subtest

We need to find out if this is a bug in WebKit or an issue with the test. We should also take the opportunity to import this test so this could be caught with EWS going forward.
Comment 1 Darin Adler 2023-02-24 13:32:34 PST 
The issue here is "transparent" vs. "none" for the default background which can be specified many ways, including "background: transparent" and "background: none".
Comment 2 Darin Adler 2023-02-24 13:36:17 PST 
Tim filed this https://github.com/w3c/csswg-drafts/issues/8496
Comment 3 Darin Adler 2023-02-26 19:53:59 PST 
We can just assume that we want this to serialize as "none" and fix it right away rather than waiting for the issues to be resolved. The fix is really easy:

1) Move "background-color" to the end of the list of longhands in CSSProperties.json for "background".

2) Rebase all the tests that change results.
Comment 4 Radar WebKit Bug Importer 2023-03-03 13:10:15 PST 
<rdar://problem/106208628>
Comment 5 Darin Adler 2023-03-05 14:06:42 PST 
Pull request: https://github.com/WebKit/WebKit/pull/11087
Comment 6 EWS 2023-03-05 17:04:07 PST 
Committed 261250@main (bec59bdd1e26): <https://commits.webkit.org/261250@main>

Reviewed commits have been landed. Closing PR #11087 and removing active labels.