Use postmaster_is_alive() check in pg_ctl restart as well as pg_ctl status,

so that restart doesn't fail when old postmaster died unbetimes.

src/bin/pg_ctl/pg_ctl.c

@@ -4,7 +4,7 @@
  *
  * Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
  *
- * $PostgreSQL: pgsql/src/bin/pg_ctl/pg_ctl.c,v 1.56 2005/04/20 23:10:16 tgl Exp $
+ * $PostgreSQL: pgsql/src/bin/pg_ctl/pg_ctl.c,v 1.57 2005/05/04 22:35:15 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -116,6 +116,7 @@ static pgpid_t get_pgpid(void);
 static char **readfile(const char *path);
 static int	start_postmaster(void);
 static bool test_postmaster_connection(void);
+static bool postmaster_is_alive(pid_t pid);
 
 static char def_postopts_file[MAXPGPATH];
 static char postopts_file[MAXPGPATH];
@@ -683,7 +684,8 @@ do_restart(void)
 
 	if (pid == 0)				/* no pid file */
 	{
-		write_stderr(_("%s: PID file \"%s\" does not exist\n"), progname, pid_file);
+		write_stderr(_("%s: PID file \"%s\" does not exist\n"),
+					 progname, pid_file);
 		write_stderr(_("Is postmaster running?\n"));
 		write_stderr(_("starting postmaster anyway\n"));
 		do_start();
@@ -692,13 +694,18 @@ do_restart(void)
 	else if (pid < 0)			/* standalone backend, not postmaster */
 	{
 		pid = -pid;
+		if (postmaster_is_alive((pid_t) pid))
+		{
 			write_stderr(_("%s: cannot restart postmaster; "
 						   "postgres is running (PID: %ld)\n"),
 						 progname, pid);
 			write_stderr(_("Please terminate postgres and try again.\n"));
 			exit(1);
 		}
+	}
 
+	if (postmaster_is_alive((pid_t) pid))
+	{
 		if (kill((pid_t) pid, sig) != 0)
 		{
 			write_stderr(_("%s: could not send stop signal (PID: %ld): %s\n"), progname, pid,
@@ -731,6 +738,14 @@ do_restart(void)
 
 		print_msg(_(" done\n"));
 		printf(_("postmaster stopped\n"));
+	}
+	else
+	{
+		write_stderr(_("%s: old postmaster process (PID: %ld) seems to be gone\n"),
+					 progname, pid);
+		write_stderr(_("starting postmaster anyway\n"));
+	}
+
 	do_start();
 }
 
@@ -841,8 +856,8 @@ do_kill(pgpid_t pid)
 {
 	if (kill((pid_t) pid, sig) != 0)
 	{
-		write_stderr(_("%s: could not send signal %d (PID: %ld): %s\n"), progname, sig, pid,
-					 strerror(errno));
+		write_stderr(_("%s: could not send signal %d (PID: %ld): %s\n"),
+					 progname, sig, pid, strerror(errno));
 		exit(1);
 	}
 }