[ES] Fix for unborn head

app/models/repository.rb

@@ -1248,16 +1248,16 @@ class Repository
     end
   end
 
+  def head_exists?
+    exists? && !empty? && !rugged.head_unborn?
+  end
+
   private
 
   def cache
     @cache ||= RepositoryCache.new(path_with_namespace, @project.id)
   end
 
-  def head_exists?
-    exists? && !empty? && !rugged.head_unborn?
-  end
-
   def file_on_head(regex)
     tree(:head).blobs.find { |file| file.name =~ regex }
   end

app/workers/elastic_commit_indexer_worker.rb

@@ -7,7 +7,7 @@ class ElasticCommitIndexerWorker
     project = Project.find(project_id)
     repository = project.repository
 
-    return true unless repository.exists? && !repository.empty?
+    return true unless repository.head_exists?
 
     indexer = Gitlab::Elastic::Indexer.new
     indexer.run(

spec/workers/elastic_commit_indexer_worker_spec.rb

@@ -18,5 +18,14 @@ describe ElasticCommitIndexerWorker do
 
       subject.perform(empty_project.id, '0000', '0000')
     end
+
+    it 'returns true if repository has unborn head' do
+      project = create :project
+      rugged = double('rugged')
+      expect(rugged).to receive(:head_unborn?).and_return(true)
+      expect_any_instance_of(Repository).to receive(:rugged).and_return(rugged)
+
+      expect(subject.perform(project.id)).to be_truthy
+    end
   end
 end