From 2016c0ed428ef8040706d704e3ff5ef8500e91ad Mon Sep 17 00:00:00 2001
From: Your Name <you@example.com>
Date: Wed, 7 Apr 2021 22:42:21 +0200
Subject: [PATCH] Fix #1176 Installing local UserCSS style fails in Firefox

Following discussion in #1176 I've used `git bisect` to find the first
failing commit as @tophf suggested. Starting from last good version `v1.5.13`
reported by @vednoc I've arrived at commit 707cd6576f2d930211be50f21362027b6cb9e873
as the first bad commit.

From what I was able to get reading the code and reproducing the error state
shown on [screenshot from original report](https://user-images.githubusercontent.com/18245694/107519428-8da8d400-6bb0-11eb-8df0-740161ec7c88.png),
it looks like the error comes from changing the logic in `downloadSelf`
event listener.

Old code used this condition for determining when to fill in `code`
value of the msg passed:

```
.then(code => ({id, code: timer && code === self.oldCode ? null : code}))
```

while new logic uses something like this (note the use of `force` flag
instead of `timer` and somewhat inverse nature of the logic):

```
.then(code => ({id, code: force || code !== self.oldCode ? code : null}))
```

What this patch does is applying both approaches: using `force` flag and
using `timer` flag at the same time. As I am myself affected by this
bug, and was able to successfully mitigate it in my environment (latest
FireFox v87.0 on Linux), I can confirm that it solves the issue and now
I'm able to install local files on FireFox again with this patch.

Please let me know if this pull request needs more formatting or
additional commits, as the
[contributions page](https://github.com/openstyles/stylus/blob/master/.github/CONTRIBUTING.md#pull-requests)
didn't mention anything specific aside from `.editorconfig` codestyle which I
think I didn't break here.

P.S.: There's a 39c1d61e11b78d5343218591ac7f5848cb3e82bb commit which
claims to fix #1176 as well, but according to my tests it doesn't make
much difference to help the bug and didn't actually solve it.
---
 content/install-hook-usercss.js | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/content/install-hook-usercss.js b/content/install-hook-usercss.js
index 42352377..dfaa8e59 100644
--- a/content/install-hook-usercss.js
+++ b/content/install-hook-usercss.js
@@ -5,11 +5,11 @@ if (typeof window.oldCode !== 'string') {
   window.oldCode = (document.querySelector('body > pre') || document.body).textContent;
   chrome.runtime.onConnect.addListener(port => {
     if (port.name !== 'downloadSelf') return;
-    port.onMessage.addListener(async ({id, force}) => {
+    port.onMessage.addListener(async ({id, force, timer}) => {
       const msg = {id};
       try {
         const code = await (await fetch(location.href, {mode: 'same-origin'})).text();
-        if (code !== window.oldCode || force) {
+        if ((code !== window.oldCode || force) || !(timer && code === window.oldCode)) {
           msg.code = window.oldCode = code;
         }
       } catch (error) {