Merge branch '41727-target-branch-name' into 'master'

Set target_branch to the ref branch when creating MR from issue

Closes #41727

See merge request gitlab-org/gitlab-ce!16422

(cherry picked from commit b4bc9bd5c5bedcd57e795f91f0668d7f2c622cde)

7e9484e9 Set target_branch to the ref branch when creating MR from issue

3 files changed, 25 insertions, 0 deletions

diff --git a/app/services/merge_requests/create_from_issue_service.rb b/app/services/merge_requests/create_from_issue_service.rb
index 89dab1dd028..cf687b71d16 100644
--- a/app/services/merge_requests/create_from_issue_service.rb
+++ b/app/services/merge_requests/create_from_issue_service.rb
@@ -54,6 +54,7 @@ module MergeRequests
         source_project_id: project.id,
         source_branch: branch_name,
         target_project_id: project.id,
+        target_branch: ref,
         milestone_id: issue.milestone_id
       }
     end
diff --git a/changelogs/unreleased/41727-target-branch-name.yml b/changelogs/unreleased/41727-target-branch-name.yml
new file mode 100644
index 00000000000..aaedf6f1d12
--- /dev/null
+++ b/changelogs/unreleased/41727-target-branch-name.yml
@@ -0,0 +1,5 @@
+---
+title: Set target_branch to the ref branch when creating MR from issue
+merge_request:
+author:
+type: fixed
diff --git a/spec/services/merge_requests/create_from_issue_service_spec.rb b/spec/services/merge_requests/create_from_issue_service_spec.rb
index 623b182b205..75553afc033 100644
--- a/spec/services/merge_requests/create_from_issue_service_spec.rb
+++ b/spec/services/merge_requests/create_from_issue_service_spec.rb
@@ -112,5 +112,24 @@ describe MergeRequests::CreateFromIssueService do
 
       expect(result[:merge_request].assignee).to eq(user)
     end
+
+    context 'when ref branch is set' do
+      subject { described_class.new(project, user, issue_iid: issue.iid, ref: 'feature').execute }
+
+      it 'sets the merge request source branch to the new issue branch' do
+        expect(subject[:merge_request].source_branch).to eq(issue.to_branch_name)
+      end
+
+      it 'sets the merge request target branch to the ref branch' do
+        expect(subject[:merge_request].target_branch).to eq('feature')
+      end
+
+      context 'when ref branch does not exist' do
+        it 'does not create a merge request' do
+          expect { described_class.new(project, user, issue_iid: issue.iid, ref: 'nobr').execute }
+            .not_to change { project.merge_requests.count }
+        end
+      end
+    end
   end
 end