bpo-32849: Always use fstat() to validate fds on POSIX #5773
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A previous approach was to usually prefer dup() for that, but there are various circumstances under which dup() succeeds for a descriptor unusable for I/O but fstat() fails with EBADF causing a fatal failure in standard streams initialization.
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| See also PR #12852. |
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| My PR #12852 is more conservative: it keeps dup() on Linux. I'm not sure why exactly, but I recall that the author of the function, @pitrou, wanted to use dup() on Linux. I'm not convinced by the O_PATH case on Linux, so I merged my conservative change instead. We can move to fstat() on Linux as well if someone comes with a more concrete example against dup(). |
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A previous approach was to usually prefer dup() for that, but
there are various circumstances under which dup() succeeds
for a descriptor unusable for I/O but fstat() fails with EBADF
causing a fatal failure in standard streams initialization.
https://bugs.python.org/issue32849