Ensure we save any older SIGALRM signal handler.

Jeremy.
(This used to be commit aa0a6f5532a2689409426eef9a4b66a28fb97635)

3 files changed, 11 insertions, 7 deletions

diff --git a/source3/lib/messages.c b/source3/lib/messages.c
index 3929f526dc..5d861b485c 100644
--- a/source3/lib/messages.c
+++ b/source3/lib/messages.c
@@ -475,6 +475,7 @@ BOOL message_named_mutex(char *name, unsigned int timeout)
 {
 	TDB_DATA key;
 	int ret;
+	void (*oldsig_handler)(int);
 
 	if (!message_init())
 		return False;
@@ -484,7 +485,7 @@ BOOL message_named_mutex(char *name, unsigned int timeout)
 
 	if (timeout) {
 		gotalarm = 0;
-		CatchSignal(SIGALRM, SIGNAL_CAST gotalarm_sig);
+		oldsig_handler = CatchSignal(SIGALRM, SIGNAL_CAST gotalarm_sig);
 		alarm(timeout);
 	}
 
@@ -492,7 +493,7 @@ BOOL message_named_mutex(char *name, unsigned int timeout)
 
 	if (timeout) {
 		alarm(0);
-		CatchSignal(SIGALRM, SIGNAL_CAST SIG_IGN);
+		CatchSignal(SIGALRM, SIGNAL_CAST oldsig_handler);
 		if (gotalarm)
 			return False;
 	}
diff --git a/source3/lib/signal.c b/source3/lib/signal.c
index 99f908235c..dceb3b53bc 100644
--- a/source3/lib/signal.c
+++ b/source3/lib/signal.c
@@ -96,10 +96,11 @@ void BlockSignals(BOOL block,int signum)
  2) The signal should be blocked during handler execution.
 ********************************************************************/
 
-void CatchSignal(int signum,void (*handler)(int ))
+void (*CatchSignal(int signum,void (*handler)(int )))(int)
 {
 #ifdef HAVE_SIGACTION
 	struct sigaction act;
+	struct sigaction oldact;
 
 	ZERO_STRUCT(act);
 
@@ -113,10 +114,11 @@ void CatchSignal(int signum,void (*handler)(int ))
 #endif
 	sigemptyset(&act.sa_mask);
 	sigaddset(&act.sa_mask,signum);
-	sigaction(signum,&act,NULL);
+	sigaction(signum,&act,&oldact);
+	return oldact.sa_handler;
 #else /* !HAVE_SIGACTION */
 	/* FIXME: need to handle sigvec and systems with broken signal() */
-	signal(signum, handler);
+	return signal(signum, handler);
 #endif
 }
 
diff --git a/source3/lib/util_file.c b/source3/lib/util_file.c
index fd3aeb99d9..883827a4f5 100644
--- a/source3/lib/util_file.c
+++ b/source3/lib/util_file.c
@@ -40,9 +40,10 @@ BOOL do_file_lock(int fd, int waitsecs, int type)
 {
   SMB_STRUCT_FLOCK lock;
   int             ret;
+  void (*oldsig_handler)(int);
 
   gotalarm = 0;
-  CatchSignal(SIGALRM, SIGNAL_CAST gotalarm_sig);
+  oldsig_handler = CatchSignal(SIGALRM, SIGNAL_CAST gotalarm_sig);
 
   lock.l_type = type;
   lock.l_whence = SEEK_SET;
@@ -54,7 +55,7 @@ BOOL do_file_lock(int fd, int waitsecs, int type)
   /* Note we must *NOT* use sys_fcntl here ! JRA */
   ret = fcntl(fd, SMB_F_SETLKW, &lock);
   alarm(0);
-  CatchSignal(SIGALRM, SIGNAL_CAST SIG_IGN);
+  CatchSignal(SIGALRM, SIGNAL_CAST oldsig_handler);
 
   if (gotalarm) {
     DEBUG(0, ("do_file_lock: failed to %s file.\n",