From d276b9b0e01ea086e48ea8327efa0f9ebddca621 Mon Sep 17 00:00:00 2001
From: "garbeam@gmail.com" <unknown>
Date: Thu, 2 Aug 2012 21:54:18 +0200
Subject: [PATCH] applied andres' multi-slock fix, thanks for spotting this
 issue

---
 slock.c | 17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)

diff --git a/slock.c b/slock.c
index 320ed2b..154a091 100644
--- a/slock.c
+++ b/slock.c
@@ -1,3 +1,4 @@
+
 /* See LICENSE file for license details. */
 #define _XOPEN_SOURCE 500
 #if HAVE_SHADOW_H
@@ -211,9 +212,9 @@ lockscreen(Display *dpy, int screen) {
 				break;
 			usleep(1000);
 		}
-		running = (len > 0);
 	}
 
+	running &= (len > 0);
 	if(!running) {
 		unlockscreen(dpy, lock);
 		lock = NULL;
@@ -257,10 +258,20 @@ main(int argc, char **argv) {
 	locks = malloc(sizeof(Lock *) * nscreens);
 	if(locks == NULL)
 		die("slock: malloc: %s", strerror(errno));
-	for(screen = 0; screen < nscreens; screen++)
-		locks[screen] = lockscreen(dpy, screen);
+	int nlocks = 0;
+	for(screen = 0; screen < nscreens; screen++) {
+		if ( (locks[screen] = lockscreen(dpy, screen)) != NULL)
+			nlocks++;
+	}
 	XSync(dpy, False);
 
+	/* Did we actually manage to lock something? */
+	if (nlocks == 0) { // nothing to protect
+		free(locks);
+		XCloseDisplay(dpy);
+		return 1;
+	}
+
 	/* Everything is now blank. Now wait for the correct password. */
 #ifdef HAVE_BSD_AUTH
 	readpw(dpy);