X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=m4%2Fpoll.m4;fp=m4%2Fpoll.m4;h=52fab91f8437fdf7bc391c6f736696ce67ba76f7;hb=1f8c872f267bc608644d6de67aa5fab6285a8533;hp=38595971d01ece9e145790aea35bea6975355948;hpb=e8eabe5a3d44bcd5ca87fba668d52203192b1645;p=gnulib.git

diff --git a/m4/poll.m4 b/m4/poll.m4
index 38595971d..52fab91f8 100644
--- a/m4/poll.m4
+++ b/m4/poll.m4
@@ -1,4 +1,4 @@
-# poll.m4 serial 11
+# poll.m4 serial 12
 dnl Copyright (c) 2003, 2005, 2006, 2007, 2009, 2010 Free Software Foundation,
 dnl Inc.
 dnl This file is free software; the Free Software Foundation
@@ -20,27 +20,30 @@ 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],