X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=m4%2Fdup2.m4;h=62e31a88d5fbb757848fabe2a5a6a65557565f40;hb=74c0798885ffd380c8f208d7aea9bd27aa6e625e;hp=bc2f417fd3bb3cedc4310e2757cc86c021bfa7cd;hpb=d60f3b0c6b0f93a601acd1cfd3923f94ca05abb0;p=gnulib.git

diff --git a/m4/dup2.m4 b/m4/dup2.m4
index bc2f417fd..62e31a88d 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,
@@ -8,24 +8,39 @@ AC_DEFUN([gl_FUNC_DUP2],
 [
   AC_REQUIRE([gl_UNISTD_H_DEFAULTS])
   AC_REQUIRE([AC_CANONICAL_HOST])
-  AC_CHECK_FUNCS_ONCE([dup2])
-  if test $ac_cv_func_dup2 = no; then
-    HAVE_DUP2=0
-    AC_LIBOBJ([dup2])
-  else
+  m4_ifdef([gl_FUNC_DUP2_OBSOLETE], [
+    AC_CHECK_FUNCS_ONCE([dup2])
+    if test $ac_cv_func_dup2 = no; then
+      HAVE_DUP2=0
+      AC_LIBOBJ([dup2])
+    fi
+  ], [
+    AC_DEFINE([HAVE_DUP2], [1], [Define to 1 if you have the 'dup2' function.])
+  ])
+  AC_CHECK_FUNCS_ONCE([fcntl])
+  if test $HAVE_DUP2 = 1; then
     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 +55,8 @@ 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])
       ])
@@ -52,6 +69,7 @@ AC_DEFUN([gl_FUNC_DUP2],
 AC_DEFUN([gl_REPLACE_DUP2],
 [
   AC_REQUIRE([gl_UNISTD_H_DEFAULTS])
+  AC_CHECK_FUNCS_ONCE([dup2])
   if test $ac_cv_func_dup2 = yes; then
     REPLACE_DUP2=1
   fi