From 4f616a932c1e56f1b4aec38420593375630bc267 Mon Sep 17 00:00:00 2001
From: Pasi Kallinen <paxed@alt.org>
Date: Sun, 1 Nov 2015 01:32:20 +0200
Subject: [PATCH] Prevent out of array access

As index() can match with the string terminator, that would make
the xdir etc array references out of bounds.
---
 src/cmd.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/cmd.c b/src/cmd.c
index 6cf2363a3..5bcd57fa5 100644
--- a/src/cmd.c
+++ b/src/cmd.c
@@ -3472,7 +3472,7 @@ char sym;
     register const char *dp = index(Cmd.dirchars, sym);
 
     u.dz = 0;
-    if (!dp)
+    if (!dp || !*dp)
         return 0;
     u.dx = xdir[dp - Cmd.dirchars];
     u.dy = ydir[dp - Cmd.dirchars];