Fix porting bug to older POSIXish platforms.

* sysdep.c (emacs_pipe): New function, that implements
pipe2 (fd, O_CLOEXEC) even on hosts that lack O_CLOEXEC.
This should port better to CentOS 5 and to Mac OS X 10.6.
All calls to pipe2 changed.

Fixes: debbugs:14862

src/ChangeLog

@@ -1,5 +1,11 @@
 2013-07-16  Paul Eggert  <eggert@cs.ucla.edu>
 
+	Fix porting bug to older POSIXish platforms (Bug#14862).
+	* sysdep.c (emacs_pipe): New function, that implements
+	pipe2 (fd, O_CLOEXEC) even on hosts that lack O_CLOEXEC.
+	This should port better to CentOS 5 and to Mac OS X 10.6.
+	All calls to pipe2 changed.
+
 	Prefer list1 (X) to Fcons (X, Qnil) when building lists.
 	This makes the code easier to read and the executable a bit smaller.
 	Do not replace all calls to Fcons that happen to create lists,

src/alloc.c

@@ -4741,7 +4741,7 @@ valid_pointer_p (void *p)
      Unfortunately, we cannot use NULL_DEVICE here, as emacs_write may
      not validate p in that case.  */
 
-  if (pipe2 (fd, O_CLOEXEC) == 0)
+  if (emacs_pipe (fd) == 0)
     {
       bool valid = emacs_write (fd[1], (char *) p, 16) == 16;
       emacs_close (fd[1]);

src/callproc.c

@@ -524,7 +524,7 @@ usage: (call-process PROGRAM &optional INFILE DESTINATION DISPLAY &rest ARGS)  *
     {
 #ifndef MSDOS
       int fd[2];
-      if (pipe2 (fd, O_CLOEXEC) != 0)
+      if (emacs_pipe (fd) != 0)
 	{
 	  int pipe_errno = errno;
 	  emacs_close (filefd);

src/emacs.c

@@ -985,7 +985,7 @@ main (int argc, char **argv)
 	 use a pipe for synchronization.  The parent waits for the child
 	 to close its end of the pipe (using `daemon-initialized')
 	 before exiting.  */
-      if (pipe2 (daemon_pipe, O_CLOEXEC) != 0)
+      if (emacs_pipe (daemon_pipe) != 0)
 	{
 	  fprintf (stderr, "Cannot pipe!\n");
 	  exit (1);

src/lisp.h

@@ -4094,6 +4094,7 @@ extern void init_random (void);
 extern void emacs_backtrace (int);
 extern _Noreturn void emacs_abort (void) NO_INLINE;
 extern int emacs_open (const char *, int, int);
+extern int emacs_pipe (int[2]);
 extern int emacs_close (int);
 extern ptrdiff_t emacs_read (int, char *, ptrdiff_t);
 extern ptrdiff_t emacs_write (int, const char *, ptrdiff_t);

src/nsterm.m

@@ -4142,7 +4142,7 @@ ns_term_init (Lisp_Object display_name)
 
   if (selfds[0] == -1)
     {
-      if (pipe2 (selfds, O_CLOEXEC) != 0)
+      if (emacs_pipe (selfds) != 0)
         {
           fprintf (stderr, "Failed to create pipe: %s\n",
                    emacs_strerror (errno));

src/process.c

@@ -1651,11 +1651,11 @@ create_process (Lisp_Object process, char **new_argv, Lisp_Object current_dir)
   else
 #endif /* HAVE_PTYS */
     {
-      if (pipe2 (sv, O_CLOEXEC) != 0)
+      if (emacs_pipe (sv) != 0)
 	report_file_error ("Creating pipe", Qnil);
       inchannel = sv[0];
       forkout = sv[1];
-      if (pipe2 (sv, O_CLOEXEC) != 0)
+      if (emacs_pipe (sv) != 0)
 	{
 	  int pipe_errno = errno;
 	  emacs_close (inchannel);
@@ -1667,7 +1667,7 @@ create_process (Lisp_Object process, char **new_argv, Lisp_Object current_dir)
     }
 
 #ifndef WINDOWSNT
-  if (pipe2 (wait_child_setup, O_CLOEXEC) != 0)
+  if (emacs_pipe (wait_child_setup) != 0)
     report_file_error ("Creating pipe", Qnil);
 #endif
 

src/sysdep.c

@@ -2201,6 +2201,20 @@ emacs_fopen (char const *file, char const *mode)
   return fd < 0 ? 0 : fdopen (fd, mode);
 }
 
+/* Create a pipe for Emacs use.  */
+
+int
+emacs_pipe (int fd[2])
+{
+  int result = pipe2 (fd, O_CLOEXEC);
+  if (! O_CLOEXEC && result == 0)
+    {
+      fcntl (fd[0], F_SETFD, FD_CLOEXEC);
+      fcntl (fd[1], F_SETFD, FD_CLOEXEC);
+    }
+  return result;
+}
+
 /* Approximate posix_close and POSIX_CLOSE_RESTART well enough for Emacs.
    For the background behind this mess, please see Austin Group defect 529
    <http://austingroupbugs.net/view.php?id=529>.  */