Fixed an issue where the link commit message did not end with a newline

changelogs/unreleased/26522-commit-message-link-line-break.yml

+---
+title: Fixed an issue where the link commit message did not end with a newline
+merge_request: 49086
+author: Kazuya Kojima
+type: fixed

lib/banzai/filter/commit_trailers_filter.rb

@@ -36,7 +36,7 @@ module Banzai
 
           next if html == content
 
-          node.replace(html)
+          node.replace("\n\n#{html}")
         end
 
         doc

spec/lib/banzai/filter/commit_trailers_filter_spec.rb

@@ -139,6 +139,12 @@ RSpec.describe Banzai::Filter::CommitTrailersFilter do
   end
 
   context "structure" do
+    it 'starts with two newlines to separate with actual commit message' do
+      doc = filter(commit_message_html)
+
+      expect(doc.xpath('pre').text).to start_with("\n\n")
+    end
+
     it 'preserves the commit trailer structure' do
       doc = filter(commit_message_html)