From e7f9edba2d78a75e90747a00758915a055a7c654 Mon Sep 17 00:00:00 2001
From: Michael Richters <gedankenexperimenter@gmail.com>
Date: Sat, 11 Nov 2017 23:46:08 -0600
Subject: [PATCH] Added a check to prevent reading past the end of the
 keymaps[] array

This relys on the 'LayerCount' variable being correct and defined in
the firmware sketch file (along with 'keymaps')
---
 src/layers.cpp | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/layers.cpp b/src/layers.cpp
index 702672a8..88f43c80 100644
--- a/src/layers.cpp
+++ b/src/layers.cpp
@@ -125,6 +125,11 @@ void Layer_::move(uint8_t layer) {
 }
 
 void Layer_::on(uint8_t layer) {
+  if (layer >= LayerCount) {
+    // Trying to turn on a layer that doesn't exist; abort
+    return;
+  }
+
   bool wasOn = isOn(layer);
 
   bitSet(LayerState, layer);