Bug 261427

media/track/track-in-band-mode.html

This test (previously only a flaky failure on macOS and iOS with a regression at 140045@main) is now consistently failing on macOS wk1.

HISTORY:

https://results.webkit.org/?suite=layout-tests&test=media%2Ftrack%2Ftrack-in-band-mode.html&platform=mac&platform=ios

CRASH LOG (preview):

2023-09-08 05:03:38.572 DumpRenderTree[59858:22213158] *** Terminating app due to uncaught exception 'NSRangeException', reason: '*** -[__NSArrayM objectAtIndex:]: index 0 beyond bounds for empty array'
*** First throw call stack:
(
	0   CoreFoundation                      0x00007ff80da3318a __exceptionPreprocess + 242
	1   libobjc.A.dylib                     0x00007ff80d55942b objc_exception_throw + 48
	2   CoreFoundation                      0x00007ff80db0d3ca -[__NSCFString characterAtIndex:].cold.1 + 0
	3   CoreFoundation                      0x00007ff80d9608ae -[__NSArrayM objectAtIndex:] + 142
	4   AVFCore                             0x00007ff82288b3d2 -[AVMediaSelectionOption _updateDisplayNameWithLocale:fallingBackToMatchingUndeterminedAndMultilingual:context:] + 96
	5   AVFCore                             0x00007ff82288b32a -[AVMediaSelectionOption _displayNameWithLocale:fallingBackToMatchingUndeterminedAndMultilingual:] + 42
...
)
libc++abi: terminating due to uncaught exception of type NSException

CRASH LOG URL:

https://build.webkit.org/results/Apple-Ventura-Debug-WK1-Tests/267782@main%20(3437)/media/track/track-in-band-mode-crash-log.txt

REPRODUCIBILITY:

I was able to reproduce this issue on macOS Ventura (13.5, 22G74/arm64) ToT on a constant basis by using the following command:

run-webkit-tests -1 --verbose --clobber-old-results --child-processes 1 media/track/track-in-band-duplicate-tracks-when-source-changes.html media/track/track-in-band-mode.html

REGRESSION:

Using contextual information (unable to perform a true bisection due to build failures), I'm inferring that the regression point is 267780@main (as the changes at this point seem directly related to the issue).

NOTE:

The test crash depends on media/track/track-in-band-duplicate-tracks-when-source-changes.html being run first.