Fix links to wiki pages with subdirectories

This commit contains the patch suggested by @fjsanpedro in the issue
covering broken links in wiki search results.

Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/56234

app/views/search/results/_wiki_blob.html.haml

 - project = find_project_for_result_blob(projects, wiki_blob)
 - wiki_blob = parse_search_result(wiki_blob)
-- wiki_blob_link = project_wiki_path(project, wiki_blob.basename)
+- wiki_blob_link = project_wiki_path(project, Pathname.new(wiki_blob.filename).sub_ext(''))
 
 = render partial: 'search/results/blob_data', locals: { blob: wiki_blob, project: project, file_name: wiki_blob.filename, blob_link: wiki_blob_link }

changelogs/unreleased/wiki-search-results-fix.yml

+---
+title: fix wiki search result links in titles
+merge_request: 27400
+author: khm
+type: fixed

spec/features/search/user_searches_for_wiki_pages_spec.rb

@@ -14,6 +14,7 @@ describe 'User searches for wiki pages', :js do
 
   include_examples 'top right search form'
 
+  shared_examples 'search wiki blobs' do
     it 'finds a page' do
       find('.js-search-project-dropdown').click
 
@@ -29,7 +30,20 @@ describe 'User searches for wiki pages', :js do
       end
 
       page.within('.results') do
-      expect(find(:css, '.search-results')).to have_link(wiki_page.title)
+        expect(find(:css, '.search-results')).to have_link(wiki_page.title, href: project_wiki_path(project, wiki_page.slug))
+      end
+    end
+  end
+
+  context 'when searching by content' do
+    it_behaves_like 'search wiki blobs' do
+      let(:search_term) { 'content' }
+    end
+  end
+
+  context 'when searching by title' do
+    it_behaves_like 'search wiki blobs' do
+      let(:search_term) { 'test_wiki' }
     end
   end
 end