From cb83c6cb603abfa9cd8945013226e17c894309f2 Mon Sep 17 00:00:00 2001 From: Eric Blake Date: Mon, 31 Dec 2012 11:15:53 -0700 Subject: [PATCH] dup2: work around cygwin bug Detected by './gnulib-tool --test dup2 cloexec'. Reported upstream: http://cygwin.com/ml/cygwin/2012-12/msg00377.html and fixed already: http://cygwin.com/ml/cygwin-cvs/2012-q4/msg00202.html but as we want to work with older cygwin, we'll have to carry this in gnulib for a while. * m4/dup2.m4 (gl_FUNC_DUP2): Flush out cygwin core dump. * lib/dup2.c (rpl_dup2): Work around it. * doc/posix-functions/dup2.texi (dup2): Document it. Signed-off-by: Eric Blake --- ChangeLog | 7 +++++++ doc/posix-functions/dup2.texi | 2 +- lib/dup2.c | 3 +++ m4/dup2.m4 | 5 ++++- 4 files changed, 15 insertions(+), 2 deletions(-) diff --git a/ChangeLog b/ChangeLog index 9d1a69ba0..af52d73a1 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,10 @@ +2012-12-31 Eric Blake + + dup2: work around cygwin bug + * m4/dup2.m4 (gl_FUNC_DUP2): Flush out cygwin core dump. + * lib/dup2.c (rpl_dup2): Work around it. + * doc/posix-functions/dup2.texi (dup2): Document it. + 2012-12-30 Paul Eggert regex: remove unnecessary dependency on localcharset.h diff --git a/doc/posix-functions/dup2.texi b/doc/posix-functions/dup2.texi index 012bb7f0e..14e5236d4 100644 --- a/doc/posix-functions/dup2.texi +++ b/doc/posix-functions/dup2.texi @@ -18,7 +18,7 @@ mingw, MSVC 9. @item This function crashes when invoked with invalid arguments on some platforms: -MSVC 9. +Cygwin 1.7.17, MSVC 9. @item This function resets the @code{FD_CLOEXEC} flag when duplicating an fd diff --git a/lib/dup2.c b/lib/dup2.c index f6d0f1c73..36b339906 100644 --- a/lib/dup2.c +++ b/lib/dup2.c @@ -95,7 +95,10 @@ rpl_dup2 (int fd, int desired_fd) # ifdef F_GETFL /* On Linux kernels 2.6.26-2.6.29, dup2 (fd, fd) returns -EBADF. On Cygwin 1.5.x, dup2 (1, 1) returns 0. + On Cygwin 1.7.17, dup2 (1, -1) dumps core. On Haiku, dup2 (fd, fd) mistakenly clears FD_CLOEXEC. */ + if (desired_fd < 0) + fd = desired_fd; if (fd == desired_fd) return fcntl (fd, F_GETFL) == -1 ? -1 : fd; # endif diff --git a/m4/dup2.m4 b/m4/dup2.m4 index fc86e8085..fa7f6d551 100644 --- a/m4/dup2.m4 +++ b/m4/dup2.m4 @@ -1,4 +1,4 @@ -#serial 18 +#serial 19 dnl Copyright (C) 2002, 2005, 2007, 2009-2012 Free Software Foundation, Inc. dnl This file is free software; the Free Software Foundation dnl gives unlimited permission to copy and/or distribute it, @@ -39,6 +39,9 @@ AC_DEFUN([gl_FUNC_DUP2], /* Many gnulib modules require POSIX conformance of EBADF. */ if (dup2 (2, 1000000) == -1 && errno != EBADF) result |= 16; + /* Flush out a cygwin core dump. */ + if (dup2 (2, -1) != -1 || errno != EBADF) + result |= 32; return result; ]) ], -- 2.11.0