Avoid double-closing on fcntl failures #2409
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Motivation: The fix provided in apple#2407 was subtly wrong. ignoreSIGPIPE, which throws the error in question, closes the FD on error _except_ on EINVAL from fcntl, where it instead does not. This inconsistent behaviour is the source of the bug. Because this behaviour is inconsistent, the fix from PR apple#2407 is also inconsistent and can in some cases double-close the socket. The actual issue is not as old as I expected: the code can be observed by reviewing the change in apple#1598, which incorrectly inserted the error transformation before the call to close. Modifications: - Revert the change from apple#2407. - Move the close in ignoreSIGPIPE to before the error check, rather than after, so we unconditionally execute it. Result: More resilient fix.
dnadoba
approved these changes
Apr 20, 2023
weissi
approved these changes
Apr 20, 2023
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Motivation:
The fix provided in #2407 was subtly wrong. ignoreSIGPIPE, which throws the error in question, closes the FD on error except on EINVAL from fcntl, where it instead does not. This inconsistent behaviour is the source of the bug. Because this behaviour is inconsistent, the fix from PR #2407 is also inconsistent and can in some cases double-close the socket.
The actual issue is not as old as I expected: the code can be observed by reviewing the change in #1598, which incorrectly inserted the error transformation before the call to close.
Modifications:
Result:
More resilient fix.