From 6f011743921db04e5513df45c5ac4b2c752d52de Mon Sep 17 00:00:00 2001
From: Aaron Marcher <me@drkhsh.at>
Date: Fri, 11 Aug 2017 14:33:02 +0200
Subject: [PATCH] Fixed possible NULL-deref and removed unnecessary
 XOpenDisplay()

- Added a check for the return value of XOpenDisplay() in main().
  This fixes a possible NULL-deref.
- Removed unnsecessary XOpenDisplay and XCloseDisplay from
  keyboard_indicators(). The ones in main() are sufficent.
---
 slstatus.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/slstatus.c b/slstatus.c
index 596d6a6..47bd4c9 100644
--- a/slstatus.c
+++ b/slstatus.c
@@ -380,10 +380,9 @@ kernel_release(void)
 static const char *
 keyboard_indicators(void)
 {
-	Display *dpy = XOpenDisplay(NULL);
 	XKeyboardState state;
+
 	XGetKeyboardControl(dpy, &state);
-	XCloseDisplay(dpy);
 
 	switch (state.led_mask) {
 		case 1:
@@ -879,6 +878,10 @@ main(int argc, char *argv[])
 
 	if (!sflag) {
 		dpy = XOpenDisplay(NULL);
+		if (!dpy) {
+			fprintf(stderr, "slstatus: cannot open display");
+			exit(1);
+		}
 	}
 
 	setlocale(LC_ALL, "");