Mercurial > hg > octave-lyh > gnulib-hg
changeset 11902:0aca807a4d5f
dup2: work around a Linux bug.
author | Bruno Haible <bruno@clisp.org> |
---|---|
date | Tue, 25 Aug 2009 10:52:51 +0200 |
parents | 98122168164f |
children | 74c6eda87050 |
files | ChangeLog doc/posix-functions/dup2.texi lib/dup2.c m4/dup2.m4 |
diffstat | 4 files changed, 39 insertions(+), 6 deletions(-) [+] |
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--- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,11 @@ +2009-08-25 Bruno Haible <bruno@clisp.org> + + dup2: work around a Linux bug. + * m4/dup2.m4 (gl_FUNC_DUP2): Test for the Linux bug. + * lib/dup2.c (rpl_dup2): Correct the return value if it is -EBADF. + * doc/posix-functions/dup2.texi: Mention the Linux bug. + Reported by Simon Josefsson. + 2009-08-25 Jim Meyering <meyering@redhat.com> libguestfs uses gnulib
--- a/doc/posix-functions/dup2.texi +++ b/doc/posix-functions/dup2.texi @@ -17,10 +17,14 @@ mingw. @item -This function returns 0 for dup2 (1, 1) on some platforms: +This function returns 0 for @code(dup2 (1, 1)} on some platforms: Cygwin 1.5.x. @item +This function may return @code{-EBADF} instead of @code{-1} on some platforms: +Linux releases between July 2008 and May 2009. + +@item This function is missing on some older platforms. @end itemize
--- a/lib/dup2.c +++ b/lib/dup2.c @@ -55,6 +55,16 @@ } # endif result = dup2 (fd, desired_fd); +# ifdef __linux__ + /* Correct a Linux return value. + <http://git.kernel.org/?p=linux/kernel/git/stable/linux-2.6.30.y.git;a=commitdiff;h=2b79bc4f7ebbd5af3c8b867968f9f15602d5f802> + */ + if (fd == desired_fd && result == (unsigned int) -EBADF) + { + errno = EBADF; + result = -1; + } +# endif if (result == 0) result = desired_fd; /* Correct a cygwin 1.5.x errno value. */
--- a/m4/dup2.m4 +++ b/m4/dup2.m4 @@ -1,4 +1,4 @@ -#serial 6 +#serial 7 dnl Copyright (C) 2002, 2005, 2007, 2009 Free Software Foundation, Inc. dnl This file is free software; the Free Software Foundation dnl gives unlimited permission to copy and/or distribute it, @@ -14,17 +14,28 @@ AC_LIBOBJ([dup2]) else AC_CACHE_CHECK([whether dup2 works], [gl_cv_func_dup2_works], - [AC_RUN_IFELSE([AC_LANG_PROGRAM([[ -#include <unistd.h> -]], [return 1 - dup2 (1, 1);])], + [AC_RUN_IFELSE([ + AC_LANG_PROGRAM([[#include <unistd.h>]], + [if (dup2 (1, 1) == 0) + return 1; + close (0); + if (dup2 (0, 0) != -1) + return 1; + return 0; + ]) + ], [gl_cv_func_dup2_works=yes], [gl_cv_func_dup2_works=no], [case "$host_os" in mingw*) # on this platform, dup2 always returns 0 for success gl_cv_func_dup2_works=no;; cygwin*) # on cygwin 1.5.x, dup2(1,1) returns 0 gl_cv_func_dup2_works=no;; + linux*) # On linux between 2008-07-27 and 2009-05-11, dup2 of a + # closed fd may yield -EBADF instead of -1 / errno=EBADF. + gl_cv_func_dup2_works=no;; *) gl_cv_func_dup2_works=yes;; - esac])]) + esac]) + ]) if test "$gl_cv_func_dup2_works" = no; then REPLACE_DUP2=1 AC_LIBOBJ([dup2])