Bug 255568

Summary:	:dir pseudo class doesn't invalidate after removing dir content attribute from document element
Product:	WebKit	Reporter:	sorvell
Component:	CSS	Assignee:	Ryosuke Niwa <rniwa>
Status:	RESOLVED FIXED
Severity:	Normal	CC:	koivisto, rniwa, simon.fraser, webkit-bug-importer, zalan
Priority:	P2	Keywords:	InRadar
Version:	Safari 16
Hardware:	Unspecified
OS:	Unspecified

Description sorvell 2023-04-17 17:56:22 PDT

When direction is dynamically changed by setting the `dir` attribute to `rtl`, styles matching `:dir(rtl)` are applied as expected; however, if the `dir` attribute is removed, styles matching `:dir(rtl)` unexpectedly still apply.

See this reproduction: https://lit.dev/playground/#gist=b7c7e390a923d0a54b5c3211bd69a668

Expected: 
1. check the `rtl` checkbox to set document to rtl mode
2. styles matching `:dir(rtl)` apply
3. uncheck the `rtl` checkbox to set document back to default (ltr) direction
4. styles matching `:dir(rtl)` do *not* apply

Actual: 
1. check the `rtl` checkbox to set document to rtl mode
2. styles matching `:dir(rtl)` apply
3. uncheck the `rtl` checkbox to set document back to default (ltr) direction
4. styles matching `:dir(rtl)` *unexpectedly do* apply

Comment 1 Radar WebKit Bug Importer 2023-04-24 17:57:19 PDT

<rdar://problem/108480507>

Comment 2 Ryosuke Niwa 2023-04-24 22:18:45 PDT

Pull request: https://github.com/WebKit/WebKit/pull/13134

Comment 3 EWS 2023-04-25 02:27:25 PDT

Committed 263357@main (a3084fe071c6): <https://commits.webkit.org/263357@main>

Reviewed commits have been landed. Closing PR #13134 and removing active labels.