Fix code and wiki search results when filename is non-ASCII

Previously, we only handled non-ASCII file contents, but the name itself can be
non-ASCII.

changelogs/unreleased/fix-code-search-500-with-non-ascii-filename.yml

+---
+title: Fix code and wiki search results when filename is non-ASCII
+merge_request:
+author:
+type: fixed

lib/gitlab/search_results.rb

@@ -7,8 +7,8 @@ module Gitlab
 
       def initialize(opts = {})
         @id = opts.fetch(:id, nil)
-        @filename = opts.fetch(:filename, nil)
-        @basename = opts.fetch(:basename, nil)
+        @filename = encode_utf8(opts.fetch(:filename, nil))
+        @basename = encode_utf8(opts.fetch(:basename, nil))
         @ref = opts.fetch(:ref, nil)
         @startline = opts.fetch(:startline, nil)
         @data = encode_utf8(opts.fetch(:data, nil))

spec/lib/gitlab/project_search_results_spec.rb

@@ -108,14 +108,26 @@ describe Gitlab::ProjectSearchResults do
 
       context 'when the search returns non-ASCII data' do
         context 'with UTF-8' do
-          let(:results) { project.repository.search_files_by_content("файл", 'master') }
+          let(:results) { project.repository.search_files_by_content('файл', 'master') }
 
           it 'returns results as UTF-8' do
             expect(subject.filename).to eq('encoding/russian.rb')
             expect(subject.basename).to eq('encoding/russian')
             expect(subject.ref).to eq('master')
             expect(subject.startline).to eq(1)
-            expect(subject.data).to eq("Хороший файл")
+            expect(subject.data).to eq('Хороший файл')
+          end
+        end
+
+        context 'with UTF-8 in the filename' do
+          let(:results) { project.repository.search_files_by_content('webhook', 'master') }
+
+          it 'returns results as UTF-8' do
+            expect(subject.filename).to eq('encoding/テスト.txt')
+            expect(subject.basename).to eq('encoding/テスト')
+            expect(subject.ref).to eq('master')
+            expect(subject.startline).to eq(3)
+            expect(subject.data).to include('WebHookの確認')
           end
         end