Bug 217240

Summary: REGRESSION (r257839): Broken focus when 'display' changes in an attribute selector
Product: WebKit Reporter: Ali Juma <ajuma>
Component: Layout and RenderingAssignee: Nobody <webkit-unassigned>
Status: RESOLVED FIXED    
Severity: Normal CC: bfulgham, cdumez, changseok, cmarcelo, darin, esprehn+autocc, ews-watchlist, gyuyoung.kim, kangil.han, koivisto, mifenton, rniwa, simon.fraser, tomoki.imai, webkit-bug-importer, wenson_hsieh, zalan
Priority: P2 Keywords: InRadar
Version: WebKit Nightly Build   
Hardware: Unspecified   
OS: Unspecified   
See Also: https://bugs.webkit.org/show_bug.cgi?id=29241
Attachments:
Description Flags
Test case
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patch
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patch
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alternative ews-feeder: commit-queue-

Description Ali Juma 2020-10-02 11:14:01 PDT 
Created attachment 410344 [details]
Test case

This is similar to bug 216754 and bug 216257 but still broken after those fixes.

The conditions needed for this bug are:
1) An element E is display:none because of an attribute selector
2) Script asks for E's computed style's display property
3) The attribute from the attribute selector changes so that E is now display:block
4) Some descendant D of E is focused using D.focus()

After r257839, we end up using the stale computed style stored at step (2) when checking for hidden ancestors in Element::isVisibleWithoutResolvingFullStyle(), so incorrectly conclude that D is not visible.

I've attached a test case. 

In practice, this is happening on m.youtube.com in Chrome for iOS, where tapping on the search button will fail to focus the search field. In that case, the code asking for the computed style is actually in Chrome's injected logic for autofill and translation. However, the attached test case reproduces the bug more generally (in MiniBrowser and Safari).
Comment 1 Radar WebKit Bug Importer 2020-10-02 12:15:12 PDT 
<rdar://problem/69891684>
Comment 2 Antti Koivisto 2021-01-12 03:05:32 PST 
Attribute change invalidation fails to invalidate the computed style.
Comment 3 Antti Koivisto 2021-01-12 03:45:44 PST 
Created attachment 417442 [details]
patch
Comment 4 Antti Koivisto 2021-01-13 04:26:29 PST 
Created attachment 417524 [details]
patch
Comment 5 Antti Koivisto 2021-01-13 05:30:44 PST 
*** Bug 220580 has been marked as a duplicate of this bug. ***
Comment 6 Antti Koivisto 2021-01-13 06:07:54 PST 
Created attachment 417527 [details]
alternative
Comment 7 Antti Koivisto 2021-01-13 11:08:27 PST 
Speedometer A/B looks good.
Comment 8 EWS 2021-01-13 11:20:48 PST 
Committed r271446: <https://trac.webkit.org/changeset/271446>

All reviewed patches have been landed. Closing bug and clearing flags on attachment 417524 [details].