dup2, dup3: work around another cygwin crasher Cygwin 1.7.25 can crash due to an off-by-one bug on an attempt to duplicate a file into the current RLIMIT_NOFILE soft limit, when that limit is smaller than the hard limit. The intent in the cygwin code was to allow the dup and auto-increase the soft limit, which is itself questionable (and which we work around in the gnulib getdtablesize module); but avoiding the crash is worth doing even if the soft limit semantics are wrong. http://cygwin.com/ml/cygwin/2013-09/msg00397.html http://cygwin.com/ml/cygwin-developers/2013-q3/msg00010.html * m4/dup2.m4 (gl_FUNC_DUP2): Expose the bug. * m4/dup3.m4 (gl_FUNC_DUP3): Likewise. * tests/test-dup2.c (main): Likewise. * lib/dup2.c (rpl_dup2): Use setdtablesize to avoid it. * lib/dup3.c (dup3): Likewise. * doc/posix-functions/dup2.texi (dup2): Document it. * doc/glibc-functions/dup3.texi (dup3): Likewise. Signed-off-by: Eric Blake <eblake@redhat.com>

@node dup3
@subsection @code{dup3}
@findex dup3

Gnulib module: dup3

Portability problems fixed by Gnulib:
@itemize
@item
This function is missing on many non-glibc platforms:
Mac OS X 10.5, FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11,
IRIX 6.5, OSF/1 5.1, Solaris 11 2011-11, Cygwin 1.7.1, mingw, MSVC 9, Interix 3.5, BeOS.

@item
This function can crash on some platforms:
Cygwin 1.7.25.
@end itemize

Portability problems not fixed by Gnulib:
@itemize
@end itemize