Bug 301807

Summary: [CSS Zoom] Page zoom should affect devicePixelRatio equally in all frames
Product: WebKit Reporter: Simon Fraser (smfr) <simon.fraser>
Component: Layout and RenderingAssignee: Matthieu Dubet <m_dubet>
Status: RESOLVED FIXED    
Severity: Normal CC: bfulgham, simon.fraser, webkit-bug-importer, zalan
Priority: P2 Keywords: InRadar
Version: WebKit Nightly Build   
Hardware: Unspecified   
OS: Unspecified   
Attachments:
Description Flags
Test case none

Simon Fraser (smfr)
Reported 2025-11-01 10:27:17 PDT
Created attachment 477251 [details] Test case The test case shows that, as of 302393@main, zooming via Comand-+ causes devicePixelRatio to not change in the main frame, but to increase in subframes. That's wrong; it should either not change, or have the same value in all subframes.
Attachments
Test case (820 bytes, text/html)
2025-11-01 10:27 PDT, Simon Fraser (smfr) 		no flags
Details
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Radar WebKit Bug Importer
Comment 1 2025-11-01 10:27:23 PDT
<rdar://problem/163857955>
Simon Fraser (smfr)
Comment 2 2025-11-01 10:29:08 PDT
Output on Command-+ n Webkit: Resize event Main frame devicePixelRatio: 2 iframe devicePixelRatio: 2.299999952316284 In Chrome: Resize event Main frame devicePixelRatio: 2.200000047683716 iframe devicePixelRatio: 2.200000047683716
Matthieu Dubet
Comment 3 2025-11-06 11:57:33 PST
Pull request: https://github.com/WebKit/WebKit/pull/53546
EWS
Comment 4 2025-11-21 09:36:28 PST
Committed 303397@main (bdfffc7361a6): <https://commits.webkit.org/303397@main> Reviewed commits have been landed. Closing PR #53546 and removing active labels.
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