xserver: Branch 'master'

[Ben Byer]

 os/utils.c |   24 ++++++++++++++++++++----
 1 file changed, 20 insertions(+), 4 deletions(-)

New commits:
diff-tree abe0a51f3f790f8c055289465e130177c4b647cc (from eb82b19aa71333b46e927516cc228f25d3e05e4d)
Author: Ben Byer <bbyer at bbyer.apple.com>
Date:   Fri Sep 21 17:07:36 2007 -0700

    So, like, checking return codes of system calls (signal, etc) is good.
    Also, only restore an old signal handler if one was actually set
    (prevents the server from dying on OS X).

diff --git a/os/utils.c b/os/utils.c
index 144098b..36c8dfe 100644
--- a/os/utils.c
+++ b/os/utils.c
@@ -285,7 +285,8 @@ OsSignal(sig, handler)
 	sigaddset(&act.sa_mask, sig);
     act.sa_flags = 0;
     act.sa_handler = handler;
-    sigaction(sig, &act, &oact);
+    if (sigaction(sig, &act, &oact))
+      perror("sigaction");
     return oact.sa_handler;
 #endif
 }
@@ -1684,6 +1685,10 @@ System(char *command)
 
 #ifdef SIGCHLD
     csig = signal(SIGCHLD, SIG_DFL);
+    if (csig == SIG_ERR) {
+      perror("signal");
+      return -1;
+    }
 #endif
 
 #ifdef DEBUG
@@ -1708,7 +1713,10 @@ System(char *command)
     }
 
 #ifdef SIGCHLD
-    signal(SIGCHLD, csig);
+    if (signal(SIGCHLD, csig) == SIG_ERR) {
+      perror("signal");
+      return -1;
+    }
 #endif
 
     return p == -1 ? -1 : status;
@@ -1745,13 +1753,18 @@ Popen(char *command, char *type)
 
     /* Ignore the smart scheduler while this is going on */
     old_alarm = signal(SIGALRM, SIG_IGN);
+    if (old_alarm == SIG_ERR) {
+      perror("signal");
+      return NULL;
+    }
 
     switch (pid = fork()) {
     case -1: 	/* error */
 	close(pdes[0]);
 	close(pdes[1]);
 	xfree(cur);
-	signal(SIGALRM, old_alarm);
+	if (signal(SIGALRM, old_alarm) == SIG_ERR)
+	  perror("signal");
 	return NULL;
     case 0:	/* child */
 	if (setgid(getgid()) == -1)
@@ -1927,7 +1940,10 @@ Pclose(pointer iop)
     /* allow EINTR again */
     OsReleaseSignals ();
     
-    signal(SIGALRM, old_alarm);
+    if (old_alarm && signal(SIGALRM, old_alarm) == SIG_ERR) {
+      perror("signal");
+      return -1;
+    }
 
     return pid == -1 ? -1 : pstat;
 }