From 2d5972f7f582916e67989efeff8bd2a04b5eef2b Mon Sep 17 00:00:00 2001
From: Ian Flanigan <flan@google.com>
Date: Fri, 4 Jan 2019 00:28:58 +0100
Subject: [PATCH] Prevent launching help when F1 is pressed

In some browsers, in particular Chrome OS, pressing F1 opens a help
screen. This can be suppressed by calling preventDefault() on the
event.
---
 js/main2e.js | 1 +
 1 file changed, 1 insertion(+)

diff --git a/js/main2e.js b/js/main2e.js
index 814973e..b2a3150 100644
--- a/js/main2e.js
+++ b/js/main2e.js
@@ -791,6 +791,7 @@ function _keydown(evt) {
     }
     if (evt.keyCode === 112) { // F1 - Reset
         cpu.reset();
+        evt.preventDefault(); // prevent launching help
     } else if (evt.keyCode === 113) { // F2 - Full Screen
         var elem = document.getElementById('screen');
         if (document.webkitCancelFullScreen) {