[Python-Dev] RE: test_file failing on Windows

[Tim Peters]

>> The MS docs don't document anything about fopen failure modes,
>> beyond that it returns NULL then.

[Jack Jansen]
> Same here with CodeWarrior on the Mac: stdio errors return NULL or -1
> and that is it, errno isn't touched, not even for fopen() file not
> found, etc.

MS does set errno in most cases; the failure to set it for bad fopen() mode
strings appears to be a bug in their code.

> If the ANSI standard requires errno to be set and people can point me
> to the right section I can submit an error report...

No such luck, Jack:  errno has always been mostly folklore in the C std, and
is almost pure folklore in C99.  The only mandatory defined errno values are
EDOM, ERANGE and EILSEQ now, and under C99 a system is never required to set
EDOM anymore, and ERANGE is required in only a handful of string->number
conversion routines now.

But if CodeWarrior claims conformance with any number of "OS-like" stds, the
latter have elaborate errno requirements; e.g., see

    http://www.opengroup.org/onlinepubs/7908799/xsh/fopen.html