ListCommitByOid isn't called with an empty batch

Batching commits for performance improvements, might lead to empty
batches being used. This isn't the case yet, but to guard against this
in future cases, a guard clause is added.

2 files changed, 12 insertions, 0 deletions

diff --git a/lib/gitlab/gitaly_client/commit_service.rb b/lib/gitlab/gitaly_client/commit_service.rb
index a4cc64de80d..7f2e6441f16 100644
--- a/lib/gitlab/gitaly_client/commit_service.rb
+++ b/lib/gitlab/gitaly_client/commit_service.rb
@@ -179,6 +179,8 @@ module Gitlab
       end
 
       def list_commits_by_oid(oids)
+        return [] if oids.empty?
+
         request = Gitaly::ListCommitsByOidRequest.new(repository: @gitaly_repo, oid: oids)
 
         response = GitalyClient.call(@repository.storage, :commit_service, :list_commits_by_oid, request, timeout: GitalyClient.medium_timeout)
diff --git a/spec/lib/gitlab/git/commit_spec.rb b/spec/lib/gitlab/git/commit_spec.rb
index 5af982c7a54..ae69a362dda 100644
--- a/spec/lib/gitlab/git/commit_spec.rb
+++ b/spec/lib/gitlab/git/commit_spec.rb
@@ -421,6 +421,16 @@ describe Gitlab::Git::Commit, seed_helper: true do
       end
     end
 
+    describe '#batch_by_oid' do
+      context 'when oids is empty' do
+        it 'makes no Gitaly request' do
+          expect(Gitlab::GitalyClient).not_to receive(:call)
+
+          described_class.batch_by_oid(repository, [])
+        end
+      end
+    end
+
     shared_examples 'extracting commit signature' do
       context 'when the commit is signed' do
         let(:commit_id) { '0b4bc9a49b562e85de7cc9e834518ea6828729b9' }