do not return random value if sigaction fails (thanks @borkovic)

1 files changed, 3 insertions, 2 deletions

diff --git a/signal.c b/signal.c
index 037be1d..68dcc27 100644
--- a/signal.c
+++ b/signal.c
@@ -15,8 +15,9 @@ void (*sys_signal(int signum, void (*handler)(int)))(int) {
 	new.sa_handler = handler;
 	new.sa_flags = 0; /* clear SA_RESTART */
 	sigfillset(&new.sa_mask);
-	sigaction(signum, &new, &old);
-	return old.sa_handler;
+	if (sigaction(signum, &new, &old) == 0)
+                return old.sa_handler;
+        return SIG_DFL;
 }
 #else
 void (*sys_signal(int signum, void (*handler)(int)))(int) {