From a70e2f13813a91bd5fd973fd5f410b4ed54ef5f1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?marcin=20miko=C5=82ajczak?= <git@mkljczk.pl>
Date: Sun, 30 Oct 2022 09:21:16 +0100
Subject: [PATCH] Check canvas export permission when initializing
 FaviconService
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Signed-off-by: marcin mikołajczak <git@mkljczk.pl>
---
 src/utils/favicon-service.ts | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/src/utils/favicon-service.ts b/src/utils/favicon-service.ts
index 805275fa5..ef372dd40 100644
--- a/src/utils/favicon-service.ts
+++ b/src/utils/favicon-service.ts
@@ -1,6 +1,22 @@
 // Adapted from Pleroma FE
 // https://git.pleroma.social/pleroma/pleroma-fe/-/blob/ef5bbc4e5f84bb9e8da76a0440eea5d656d36977/src/services/favicon_service/favicon_service.js
 
+const checkCanvasExtractPermission = () => {
+  const canvas = document.createElement('canvas');
+  canvas.width = 1;
+  canvas.height = 1;
+
+  const ctx = canvas.getContext('2d')!;
+  if (!ctx) return false;
+
+  ctx.fillStyle = '#0482d8';
+  ctx.fillRect(0, 0, 1, 1);
+
+  const { data } = ctx.getImageData(0, 0, 1, 1);
+
+  return data.join(',') === '4,130,216,255';
+};
+
 type Favicon = {
   favcanvas: HTMLCanvasElement;
   favimg: HTMLImageElement;
@@ -17,6 +33,8 @@ const createFaviconService = () => {
 
   /** Start the favicon service */
   const initFaviconService = (): void => {
+    if (!checkCanvasExtractPermission()) return;
+
     const nodes: NodeListOf<HTMLLinkElement> = document.querySelectorAll('link[rel="icon"]');
     nodes.forEach(favicon => {
       if (favicon) {