From d183779fb597695a08914b6e9dfe6e16e972e468 Mon Sep 17 00:00:00 2001
From: tophf <tophf@gmx.com>
Date: Tue, 10 Nov 2020 21:40:50 +0300
Subject: [PATCH] accept any content-type for text/ except text/html

---
 background/usercss-install-helper.js | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/background/usercss-install-helper.js b/background/usercss-install-helper.js
index b854564a..b0fbb593 100644
--- a/background/usercss-install-helper.js
+++ b/background/usercss-install-helper.js
@@ -4,7 +4,8 @@
 (() => {
   const installCodeCache = {};
   const clearInstallCode = url => delete installCodeCache[url];
-  const isContentTypeText = type => /^text\/(css|plain)(;.*?)?$/i.test(type);
+  /** Sites may be using custom types like text/stylus so this coarse filter only excludes html */
+  const isContentTypeText = type => /^text\/(?!html)/i.test(type);
 
   // in Firefox we have to use a content script to read file://
   const fileLoader = !chrome.app && (