From 4de5d20368d4b2ca4f0851eafa900cd0c9a3c691 Mon Sep 17 00:00:00 2001
From: Ben Harris <bjh21@bjh21.me.uk>
Date: Mon, 3 Apr 2023 22:11:42 +0100
Subject: [PATCH] js: use the "load" event for loading save files

This is in place of the "loadend" event.  In Chromium, (and in the
specification), "loadend" is triggered not only when the file is
loaded but also when loading fails.  Obviously when loading fails we
don't want to try to parse the (nonexistent) resulting file.

Using the "load" event works better, since it's only fired on success,
and we can also have an "error" handler to report problems with
loading files, albeit with no detail at all.

This doesn't seem to make any difference in Firefox, which in my
testing fires "load" and "loadend" on success and nothing at all on
failure.
---
 emccpre.js | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/emccpre.js b/emccpre.js
index 837f815..7c68445 100644
--- a/emccpre.js
+++ b/emccpre.js
@@ -462,7 +462,7 @@ function initPuzzle() {
                 if (input.files.length == 1) {
                     var file = input.files.item(0);
                     var reader = new FileReader();
-                    reader.addEventListener("loadend", function() {
+                    reader.addEventListener("load", function() {
                         var pos = 0;
                         savefile_read_callback = function(buf, len) {
                             if (pos + len > reader.result.byteLength)
@@ -475,6 +475,9 @@ function initPuzzle() {
                         load_game();
                         savefile_read_callback = null;
                     });
+                    reader.addEventListener("error", function() {
+                        alert("An error occured while loading the file");
+                    });
                     reader.readAsArrayBuffer(file);
                 }
             });