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[PATCH] dup2: work around Haiku bug
From: |
Eric Blake |
Subject: |
[PATCH] dup2: work around Haiku bug |
Date: |
Mon, 31 Jan 2011 21:00:43 -0700 |
dup2(n,n) must be a no-op, but on Haiku, it resets FD_CLOEXEC.
However, we must keep the Linux workaround for dup2(n,n)
returning (unsigned int)-EBADF.
* m4/dup2.m4 (gl_FUNC_DUP2): Test for bug.
* lib/dup2.c (rpl_dup2) [!WIN32]: Add workaround.
* doc/posix-functions/dup2.texi (dup2): Document the bug.
* tests/test-dup2.c (main): Enhance test.
Signed-off-by: Eric Blake <address@hidden>
---
This fixes './gnulib-tool --with-tests --test dup2 cloexec' on Haiku.
ChangeLog | 8 ++++++++
doc/posix-functions/dup2.texi | 5 +++++
lib/dup2.c | 4 ++++
m4/dup2.m4 | 23 +++++++++++++++++------
tests/test-dup2.c | 5 +++++
5 files changed, 39 insertions(+), 6 deletions(-)
diff --git a/ChangeLog b/ChangeLog
index 360f0dd..b025454 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+2011-01-31 Eric Blake <address@hidden>
+
+ dup2: work around Haiku bug
+ * m4/dup2.m4 (gl_FUNC_DUP2): Test for bug.
+ * lib/dup2.c (rpl_dup2) [!WIN32]: Add workaround.
+ * doc/posix-functions/dup2.texi (dup2): Document the bug.
+ * tests/test-dup2.c (main): Enhance test.
+
2011-01-31 Simon Josefsson <address@hidden>
doc: off_t is not available in eglibc 2.11.2 stdio.h.
diff --git a/doc/posix-functions/dup2.texi b/doc/posix-functions/dup2.texi
index 59bad08..fc1e359 100644
--- a/doc/posix-functions/dup2.texi
+++ b/doc/posix-functions/dup2.texi
@@ -17,6 +17,11 @@ dup2
mingw.
@item
+This function resets the @code{FD_CLOEXEC} flag when duplicating an fd
+to itself on some platforms:
+Haiku.
+
address@hidden
This function returns 0 for @code{dup2 (1, 1)} on some platforms:
Cygwin 1.5.x.
diff --git a/lib/dup2.c b/lib/dup2.c
index 6b72f7b..e00dc7b 100644
--- a/lib/dup2.c
+++ b/lib/dup2.c
@@ -59,6 +59,10 @@ rpl_dup2 (int fd, int desired_fd)
errno = EBADF;
return -1;
}
+# elif !defined __linux__
+ /* On Haiku, dup2 (fd, fd) mistakenly clears FD_CLOEXEC. */
+ if (fd == desired_fd)
+ return fcntl (fd, F_GETFL) == -1 ? -1 : fd;
# endif
result = dup2 (fd, desired_fd);
# ifdef __linux__
diff --git a/m4/dup2.m4 b/m4/dup2.m4
index bc2f417..def263b 100644
--- a/m4/dup2.m4
+++ b/m4/dup2.m4
@@ -1,4 +1,4 @@
-#serial 11
+#serial 12
dnl Copyright (C) 2002, 2005, 2007, 2009-2011 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
@@ -8,7 +8,7 @@ AC_DEFUN([gl_FUNC_DUP2],
[
AC_REQUIRE([gl_UNISTD_H_DEFAULTS])
AC_REQUIRE([AC_CANONICAL_HOST])
- AC_CHECK_FUNCS_ONCE([dup2])
+ AC_CHECK_FUNCS_ONCE([dup2 fcntl])
if test $ac_cv_func_dup2 = no; then
HAVE_DUP2=0
AC_LIBOBJ([dup2])
@@ -16,16 +16,25 @@ AC_DEFUN([gl_FUNC_DUP2],
AC_CACHE_CHECK([whether dup2 works], [gl_cv_func_dup2_works],
[AC_RUN_IFELSE([
AC_LANG_PROGRAM([[#include <unistd.h>
+#include <fcntl.h>
#include <errno.h>]],
[int result = 0;
- if (dup2 (1, 1) == 0)
+#if HAVE_FCNTL
+ if (fcntl (1, F_SETFD, FD_CLOEXEC) == -1)
result |= 1;
+#endif HAVE_FCNTL
+ if (dup2 (1, 1) == 0)
+ result |= 2;
+#if HAVE_FCNTL
+ if (fcntl (1, F_GETFD) != FD_CLOEXEC)
+ result |= 4;
+#endif
close (0);
if (dup2 (0, 0) != -1)
- result |= 2;
+ result |= 8;
/* Many gnulib modules require POSIX conformance of EBADF. */
- if (dup2 (1, 1000000) == -1 && errno != EBADF)
- result |= 4;
+ if (dup2 (2, 1000000) == -1 && errno != EBADF)
+ result |= 16;
return result;
])
],
@@ -40,6 +49,8 @@ AC_DEFUN([gl_FUNC_DUP2],
gl_cv_func_dup2_works=no;;
freebsd*) # on FreeBSD 6.1, dup2(1,1000000) gives EMFILE, not EBADF.
gl_cv_func_dup2_works=no;;
+ haiku*) # on Haiku alpha 2, dup2(1, 1) resets FD_CLOEXEC.
+ gl_cv_func_dup2_works=no;;
*) gl_cv_func_dup2_works=yes;;
esac])
])
diff --git a/tests/test-dup2.c b/tests/test-dup2.c
index 35aa6ca..e2ad88b 100644
--- a/tests/test-dup2.c
+++ b/tests/test-dup2.c
@@ -169,7 +169,12 @@ main (void)
ASSERT (dup2 (fd + 1, fd + 1) == fd + 1);
ASSERT (!is_inheritable (fd + 1));
ASSERT (dup2 (fd + 1, fd + 2) == fd + 2);
+ ASSERT (!is_inheritable (fd + 1));
ASSERT (is_inheritable (fd + 2));
+ errno = 0;
+ ASSERT (dup2 (fd + 1, -1) == -1);
+ ASSERT (errno == EBADF);
+ ASSERT (!is_inheritable (fd + 1));
#endif
/* On systems that distinguish between text and binary mode, dup2
--
1.7.3.5