From b74ad8634ba43f44d5b40dae6e7b9597d6b4f5e0 Mon Sep 17 00:00:00 2001
From: David Baker <dave@matrix.org>
Date: Thu, 19 Oct 2017 17:16:52 +0100
Subject: [PATCH] Use object URLs to load Files in to images

Fixes https://github.com/vector-im/riot-web/issues/5326
---
 src/ContentMessages.js | 20 +++++++-------------
 1 file changed, 7 insertions(+), 13 deletions(-)

diff --git a/src/ContentMessages.js b/src/ContentMessages.js
index 00728061a2..8d40b65124 100644
--- a/src/ContentMessages.js
+++ b/src/ContentMessages.js
@@ -99,23 +99,17 @@ function loadImageElement(imageFile) {
 
     // Load the file into an html element
     const img = document.createElement("img");
+    const objectUrl = URL.createObjectURL(imageFile);
+    img.src = objectUrl;
 
-    const reader = new FileReader();
-    reader.onload = function(e) {
-        img.src = e.target.result;
-
-        // Once ready, create a thumbnail
-        img.onload = function() {
-            deferred.resolve(img);
-        };
-        img.onerror = function(e) {
-            deferred.reject(e);
-        };
+    // Once ready, create a thumbnail
+    img.onload = function() {
+        URL.revokeObjectURL(objectUrl);
+        deferred.resolve(img);
     };
-    reader.onerror = function(e) {
+    img.onerror = function(e) {
         deferred.reject(e);
     };
-    reader.readAsDataURL(imageFile);
 
     return deferred.promise;
 }