From 84768d505ca5ca7726af89702662c0f271323915 Mon Sep 17 00:00:00 2001
From: Gergely Nagy <algernon@madhouse-project.org>
Date: Tue, 8 Aug 2017 16:02:53 +0200
Subject: [PATCH] Layer_::updateKeyCache: Guard against out of bounds key
 coordinates

It may happen that we get passed an UNKNOWN_KEYSWITCH_LOCATION, which will
always be out of bounds. Lets not corrupt random memory when in this situation,
but instead, return quickly.

Signed-off-by: Gergely Nagy <algernon@madhouse-project.org>
---
 src/layers.cpp | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/layers.cpp b/src/layers.cpp
index c05bde63..694e98c5 100644
--- a/src/layers.cpp
+++ b/src/layers.cpp
@@ -84,6 +84,9 @@ void
 Layer_::updateKeyCache(byte row, byte col) {
   int8_t layer = highestLayer;
 
+  if (row >= ROWS || col >= COLS)
+    return;
+
   for (layer = highestLayer; layer >= DefaultLayer; layer--) {
     if (Layer.isOn(layer)) {
       Key mappedKey = (*getKey)(layer, row, col);