Bug 1752107 - Allow adding Reddit threads to "See Also"

Bugzilla/BugUrl.pm

@@ -75,6 +75,7 @@ use constant SUB_CLASSES => qw(
   Bugzilla::BugUrl::Splat
   Bugzilla::BugUrl::Phabricator
   Bugzilla::BugUrl::ConnectMozOrg
+  Bugzilla::BugUrl::Reddit
 );
 
 ###############################

Bugzilla/BugUrl/Reddit.pm

@@ -0,0 +1,32 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+#
+# This Source Code Form is "Incompatible With Secondary Licenses", as
+# defined by the Mozilla Public License, v. 2.0.
+
+package Bugzilla::BugUrl::Reddit;
+
+use 5.10.1;
+use strict;
+use warnings;
+
+use base qw(Bugzilla::BugUrl);
+
+###############################
+####        Methods        ####
+###############################
+
+sub should_handle {
+  my ($class, $uri) = @_;
+  return (lc($uri->authority) eq 'www.reddit.com'
+      and $uri->path =~ /^\/r\//) ? 1 : 0;
+}
+
+sub _check_value {
+  my ($class, $uri) = @_;
+  $uri = $class->SUPER::_check_value($uri);
+  return $uri;
+}
+
+1;

template/en/default/global/user-error.html.tmpl

@@ -340,6 +340,7 @@
         <li>A revision, support ticket, or task in Phabricator.</li>
         <li>A Mozilla Sentry issue.</li>
         <li>An idea or discussion topic on connect.mozilla.org</li>
+        <li>A discussion topic on www.reddit.com</li>
       </ul>
     [% ELSIF reason == 'id' %]
       There is no valid [% terms.bug %] id in that URL.