Correctly detect multiple issue URLs after 'Closes...' in MR descriptions

changelogs/unreleased/dm-closing-issue-urls.yml

+---
+title: Correctly detect multiple issue URLs after 'Closes...' in MR descriptions
+merge_request:
+author:
+type: fixed

lib/gitlab/closing_issue_extractor.rb

 module Gitlab
   class ClosingIssueExtractor
     ISSUE_CLOSING_REGEX = begin
-      link_pattern = URI.regexp(%w(http https))
+      link_pattern = Banzai::Filter::AutolinkFilter::LINK_PATTERN
 
       pattern = Gitlab.config.gitlab.issue_closing_pattern
       pattern = pattern.sub('%{issue_ref}', "(?:(?:#{link_pattern})|(?:#{Issue.reference_pattern}))")

spec/lib/gitlab/closing_issue_extractor_spec.rb

@@ -347,10 +347,10 @@ describe Gitlab::ClosingIssueExtractor do
       end
 
       it "fetches cross-project URL references" do
-        message = "Closes #{urls.project_issue_url(issue2.project, issue2)} and #{reference}"
+        message = "Closes #{urls.project_issue_url(issue2.project, issue2)}, #{reference} and #{urls.project_issue_url(other_issue.project, other_issue)}"
 
         expect(subject.closed_by_message(message))
-            .to match_array([issue, issue2])
+            .to match_array([issue, issue2, other_issue])
       end
 
       it "ignores invalid cross-project URL references" do