Ensure links in notifications footer are not escaped

Signed-off-by: Rémy Coutable <remy@rymai.me>

app/views/layouts/notify.html.haml

@@ -14,7 +14,7 @@
         %br
         - if @target_url
           - if @reply_by_email
-            = _('Reply to this email directly or %{view_it_on_gitlab}.') % { view_it_on_gitlab: link_to(_("view it on GitLab"), @target_url) }
+            = _('Reply to this email directly or %{view_it_on_gitlab}.').html_safe % { view_it_on_gitlab: link_to(_("view it on GitLab"), @target_url) }
           - else
             #{link_to _("View it on GitLab"), @target_url}.
           %br

changelogs/unreleased/49899-merge-request-e-mail-link-has-full-url.yml

+---
+title: Ensure links in notifications footer are not escaped
+merge_request: 21000
+author:
+type: fixed

spec/support/shared_examples/notify_shared_examples.rb

@@ -87,6 +87,10 @@ shared_examples 'an email starting a new thread with reply-by-email enabled' do
   include_examples 'an email with X-GitLab headers containing project details'
   include_examples 'a new thread email with reply-by-email enabled'
 
+  it 'includes "Reply to this email directly or <View it on GitLab>"' do
+    expect(subject.default_part.body).to include(%(Reply to this email directly or <a href="#{Gitlab::UrlBuilder.build(model)}">view it on GitLab</a>.))
+  end
+
   context 'when reply-by-email is enabled with incoming address with %{key}' do
     it 'has a Reply-To header' do
       is_expected.to have_header 'Reply-To', /<reply+(.*)@#{Gitlab.config.gitlab.host}>\Z/