set old WM_NAME content before exiting

slstatus.c

@@ -592,7 +592,7 @@ main(void)
 {
 	size_t i;
 	char status_string[4096];
-	char *res, *element;
+	char *res, *element, *status_old;
 	struct arg argument;
 	struct sigaction act;
 
@@ -603,6 +603,8 @@ main(void)
 
 	dpy = XOpenDisplay(NULL);
 
+	XFetchName(dpy, DefaultRootWindow(dpy), &status_old);
+
 	while (!done) {
 		status_string[0] = '\0';
 		for (i = 0; i < sizeof(args) / sizeof(args[0]); ++i) {
@@ -630,6 +632,9 @@ main(void)
 		delay = 0;
 	}
 
+	XStoreName(dpy, DefaultRootWindow(dpy), status_old);
+	XSync(dpy, False);
+
 	XCloseDisplay(dpy);
 
 	return 0;