Process-swapping may occur even though opener has handle to openee, which is not Web-compatible. The reason is that we rely on the window not having an opener to process-swap. However, the opener can be disowned, which does not mean that the opener doesn't still have a handle to its openee.
Created attachment 356315 [details] Patch
Attachment 356315 [details] did not pass style-queue: ERROR: Tools/TestWebKitAPI/Tests/WebKitCocoa/ProcessSwapOnNavigation.mm:2980: Multi-line string ("...") found. This lint script doesn't do well with such strings, and may give bogus warnings. They're ugly and unnecessary, and you should use concatenation instead". [readability/multiline_string] [5] ERROR: Tools/TestWebKitAPI/Tests/WebKitCocoa/ProcessSwapOnNavigation.mm:2988: Multi-line string ("...") found. This lint script doesn't do well with such strings, and may give bogus warnings. They're ugly and unnecessary, and you should use concatenation instead". [readability/multiline_string] [5] Total errors found: 2 in 14 files If any of these errors are false positives, please file a bug against check-webkit-style.
Comment on attachment 356315 [details] Patch Clearing flags on attachment: 356315 Committed r238787: <https://trac.webkit.org/changeset/238787>
All reviewed patches have been landed. Closing bug.
<rdar://problem/46398357>