From 559b180a1483f50065094c91d4619a8a8e736377 Mon Sep 17 00:00:00 2001
From: Tissevert <tissevert+devel@marvid.fr>
Date: Sat, 29 Dec 2018 14:45:47 +0100
Subject: [PATCH] Check that a button mapping is defined before accessing it

---
 src/js/buttons.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/js/buttons.js b/src/js/buttons.js
index 731312f..6e7d295 100644
--- a/src/js/buttons.js
+++ b/src/js/buttons.js
@@ -14,7 +14,7 @@ function Buttons(session) {
 
 	document.addEventListener('keydown', function(event) {
 		var button = session.get('options').layout[event.key];
-		if(button != undefined && mapping[button] != undefined) {
+		if(button != undefined && mapping != undefined && mapping[button] != undefined) {
 			event.preventDefault();
 			mapping[button]();
 		}