NEWS.stable: log cherry-pick [a5a35f0]->[c4596b1] freopen: Documentation.

[gnulib.git] / m4 / poll.m4

diff --git a/m4/poll.m4 b/m4/poll.m4
index 9cb02d5..e489df7 100644 (file)
--- a/m4/poll.m4
+++ b/m4/poll.m4
@@ -1,6 +1,5 @@
-# poll.m4 serial 10
-dnl Copyright (c) 2003, 2005, 2006, 2007, 2009, 2010 Free Software Foundation,
-dnl Inc.
+# poll.m4 serial 14
+dnl Copyright (c) 2003, 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,
 dnl with or without modifications, as long as this notice is preserved.
@@ -20,27 +19,30 @@ AC_DEFUN([gl_FUNC_POLL],
 #include <poll.h>
          int main()
          {
+           int result = 0;
            struct pollfd ufd;
            /* Try /dev/null for reading.  */
            ufd.fd = open ("/dev/null", O_RDONLY);
-           if (ufd.fd < 0)
-             /* If /dev/null does not exist, it's not MacOS X nor AIX. */
-             return 0;
-           ufd.events = POLLIN;
-           ufd.revents = 0;
-           if (!(poll (&ufd, 1, 0) == 1 && ufd.revents == POLLIN))
-             return 1;
+           /* If /dev/null does not exist, it's not MacOS X nor AIX. */
+           if (ufd.fd >= 0)
+             {
+               ufd.events = POLLIN;
+               ufd.revents = 0;
+               if (!(poll (&ufd, 1, 0) == 1 && ufd.revents == POLLIN))
+                 result |= 1;
+             }
            /* Try /dev/null for writing.  */
            ufd.fd = open ("/dev/null", O_WRONLY);
-           if (ufd.fd < 0)
-             /* If /dev/null does not exist, it's not MacOS X nor AIX. */
-             return 0;
-           ufd.events = POLLOUT;
-           ufd.revents = 0;
-           if (!(poll (&ufd, 1, 0) == 1 && ufd.revents == POLLOUT))
-             return 1;
+           /* If /dev/null does not exist, it's not MacOS X nor AIX. */
+           if (ufd.fd >= 0)
+             {
+               ufd.events = POLLOUT;
+               ufd.revents = 0;
+               if (!(poll (&ufd, 1, 0) == 1 && ufd.revents == POLLOUT))
+                 result |= 2;
+             }
            /* Trying /dev/tty may be too environment dependent.  */
-           return 0;
+           return result;
          }]])],
          [gl_cv_func_poll=yes],
          [gl_cv_func_poll=no],
@@ -60,10 +62,8 @@ This is MacOSX or AIX
       REPLACE_POLL=1
     fi
   fi
-  if test $HAVE_POLL = 0 || $REPLACE_POLL = 1; then
-    gl_REPLACE_POLL_H
-    AC_LIBOBJ([poll])
-    gl_PREREQ_POLL
+  if test $HAVE_POLL = 0 || test $REPLACE_POLL = 1; then
+    :
   else
     AC_DEFINE([HAVE_POLL], [1],
       [Define to 1 if you have the 'poll' function and it works.])