From f7540aa52f1f2eb97cd111890187132871463cf1 Mon Sep 17 00:00:00 2001
From: ValdikSS <iam@valdikss.org.ru>
Date: Mon, 25 Apr 2022 19:57:56 +0300
Subject: [PATCH] FIX: properly clean Thunderbird emails, don't remove links
 (#16543)

Mozilla Thunderbird email client add links into HTML as follows:

`<p>The link: <a class="moz-txt-link-freetext" href="https://google.com">https://google.com</a></p>`

Current filtering rules strip out the link, leaving only `<p>The link: </p>`.
Properly strip only unnecessary information: quote prefix, signature, forwarded message header.
---
 lib/email/receiver.rb | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/lib/email/receiver.rb b/lib/email/receiver.rb
index e03368a3616..ff01667ef19 100644
--- a/lib/email/receiver.rb
+++ b/lib/email/receiver.rb
@@ -471,7 +471,9 @@ module Email
     def extract_from_mozilla(doc)
       # Mozilla (Thunderbird ?) properly identifies signature and forwarded emails
       # Remove them and anything that comes after
-      elided = doc.css("*[class^='moz-'], *[class^='moz-'] ~ *").remove
+      elided = doc.css("*[class^='moz-cite'], *[class^='moz-cite'] ~ *, " \
+                       "*[class^='moz-signature'], *[class^='moz-signature'] ~ *, " \
+                       "*[class^='moz-forward'], *[class^='moz-forward'] ~ *").remove
       to_markdown(doc.to_html, elided.to_html)
     end