Fix issue #3055 (project search with unmatched parentheses)

app/models/repository.rb

@@ -482,7 +482,7 @@ class Repository
   def search_files(query, ref)
     offset = 2
-    args = %W(git grep -i -n --before-context #{offset} --after-context #{offset} #{query} #{ref || root_ref})
+    args = %W(git grep -i -n --before-context #{offset} --after-context #{offset} -e #{query} #{ref || root_ref})
     Gitlab::Popen.popen(args, path_to_repo).first.scrub.split(/^--$/)
   end

lib/gitlab/project_search_results.rb

@@ -9,7 +9,7 @@ module Gitlab
                         else
                           nil
                         end
-      @query = Shellwords.shellescape(query) if query.present?
+      @query = query
     end
     def objects(scope, page = nil)

spec/lib/gitlab/project_search_results_spec.rb

@@ -9,7 +9,7 @@ describe Gitlab::ProjectSearchResults do
     it { expect(results.project).to eq(project) }
     it { expect(results.repository_ref).to be_nil }
-    it { expect(results.query).to eq('hello\\ world') }
+    it { expect(results.query).to eq('hello world') }
   end
   describe 'initialize with ref' do
@@ -18,6 +18,6 @@ describe Gitlab::ProjectSearchResults do
     it { expect(results.project).to eq(project) }
     it { expect(results.repository_ref).to eq(ref) }
-    it { expect(results.query).to eq('hello\\ world') }
+    it { expect(results.query).to eq('hello world') }
   end
 end