Bug 312575

Summary: Showing an alert in fullscreenchange event handler freezes WebContent process, navigating back sometimes causes Safari crash
Product: WebKit Reporter: Kagami Sascha Rosylight <krosylight>
Component: DOMAssignee: Rob Buis <rbuis>
Status: NEW    
Severity: Normal CC: cdumez, fred.wang, jer.noble, webkit-bug-importer
Priority: P2 Keywords: InRadar
Version: Safari Technology Preview   
Hardware: Unspecified   
OS: Unspecified   
See Also: https://bugs.webkit.org/show_bug.cgi?id=247331
https://bugs.webkit.org/show_bug.cgi?id=108230
Bug Depends on:    
Bug Blocks: 276855    
Attachments:
Description Flags
repro.html
none
repro.html none

Kagami Sascha Rosylight
Reported 2026-04-17 08:13:02 PDT
1. Open example.com 2. Open the attachment here by pasting the URL 3. (Observe the disappearance of the tab) 4. Navigate back 5. (See Safari exits, with a crash report)
Attachments
repro.html (deleted)
2026-04-17 08:13 PDT, Kagami Sascha Rosylight 		no flags
Details
repro.html (175 bytes, text/html)
2026-04-17 08:14 PDT, Kagami Sascha Rosylight 		no flags
Details
Show Obsolete (1) View All Add attachment proposed patch, testcase, etc.
Kagami Sascha Rosylight
Comment 1 2026-04-17 08:14:21 PDT
Created attachment 479137 [details] repro.html (my attachment was immediately deleted?)
Alexey Proskuryakov
Comment 2 2026-04-19 12:35:37 PDT
Thank you for the report, I can reproduce as described, except that the "fullscreen" button needs to be pressed after step 2. The tab goes blank because WebContent process is frozen waiting for the alert to be displayed. Step 1 with example.com is needed to reproduce the crash on going back, the freeze reproduces without it. > (my attachment was immediately deleted?) https://bugs.webkit.org/show_activity.cgi?id=312575 shows that it was marked as obsolete. It's still visible by clicking "Show Obsolete" under the attachments.
Radar WebKit Bug Importer
Comment 3 2026-04-19 12:35:44 PDT
<rdar://problem/175121275>
Frédéric Wang Nélar
Comment 4 2026-10-12 09:13:27 PDT
I'm not entirely sure I can reproduce the crash/freeze, but the back/forward buttons are definitely broken with a blank page showing up, similarly to bug 108230.
Rob Buis
Comment 5 2026-10-22 03:48:09 PDT
Pull request: https://github.com/WebKit/WebKit/pull/77887
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