Merge branch 'ajk-safe-wiki-event-url' into 'master'

Ensure we always generate a valid URL

Closes #220932

See merge request gitlab-org/gitlab!34191

app/helpers/events_helper.rb

@@ -188,7 +188,7 @@ module EventsHelper
   end
 
   def event_wiki_page_target_url(event)
-    project_wiki_url(event.project, event.target.canonical_slug)
+    project_wiki_url(event.project, event.target&.canonical_slug || Wiki::HOMEPAGE)
   end
 
   def event_note_title_html(event)

changelogs/unreleased/ajk-safe-wiki-event-url.yml

+---
+title: Ensure we always generate a valid wiki event URL
+merge_request: 34191
+author:
+type: fixed

spec/helpers/events_helper_spec.rb

@@ -150,6 +150,21 @@ describe EventsHelper do
 
       expect(helper.event_wiki_page_target_url(event)).to eq(url)
     end
+
+    context 'there is no canonical slug' do
+      let(:event) { create(:wiki_page_event, project: project) }
+
+      before do
+        event.target.slugs.update_all(canonical: false)
+        event.target.clear_memoization(:canonical_slug)
+      end
+
+      it 'links to the home page' do
+        url = helper.project_wiki_url(project, Wiki::HOMEPAGE)
+
+        expect(helper.event_wiki_page_target_url(event)).to eq(url)
+      end
+    end
   end
 
   describe '#event_wiki_title_html' do