Merge branch 'osw-remove-transaction-while-rebasing' into 'master'

Remove DB transaction from Rebase Gitaly operation

See merge request gitlab-org/gitlab!20739

app/models/repository.rb

@@ -1052,7 +1052,6 @@ class Repository
       return rebase_deprecated(user, merge_request)
     end
 
-    MergeRequest.transaction do
     raw.rebase(
       user,
       merge_request.id,
@@ -1063,7 +1062,9 @@ class Repository
     ) do |commit_id|
       merge_request.update!(rebase_commit_sha: commit_id, merge_error: nil)
     end
-    end
+  rescue StandardError => error
+    merge_request.update!(rebase_commit_sha: nil)
+    raise error
   end
 
   def squash(user, merge_request, message)

changelogs/unreleased/osw-remove-transaction-while-rebasing.yml

+---
+title: Remove DB transaction from Rebase operation
+merge_request: 20739
+author:
+type: fixed

spec/models/repository_spec.rb

@@ -1530,7 +1530,7 @@ describe Repository do
           expect(merge_request.reload.rebase_commit_sha).to eq(new_sha)
         end
 
-        it 'does rollback when an error is encountered in the second step' do
+        it 'does rollback when a PreReceiveError is encountered in the second step' do
           second_response = double(pre_receive_error: 'my_error', git_error: nil)
           mock_gitaly(second_response)
 
@@ -1541,6 +1541,17 @@ describe Repository do
           expect(merge_request.reload.rebase_commit_sha).to be_nil
         end
 
+        it 'does rollback when a GitError is encountered in the second step' do
+          second_response = double(pre_receive_error: nil, git_error: 'git error')
+          mock_gitaly(second_response)
+
+          expect do
+            repository.rebase(user, merge_request)
+          end.to raise_error(Gitlab::Git::Repository::GitError)
+
+          expect(merge_request.reload.rebase_commit_sha).to be_nil
+        end
+
         def mock_gitaly(second_response)
           responses = [
             double(rebase_sha: new_sha).as_null_object,