allow rebase for unapproved merge requests

app/controllers/ee/projects/merge_requests_controller.rb

@@ -15,7 +15,6 @@ module EE
 
       def rebase
         return access_denied! unless @merge_request.can_be_merged_by?(current_user)
-        return render_404 unless @merge_request.approved?
 
         RebaseWorker.perform_async(@merge_request.id, current_user.id)
 

changelogs/unreleased-ee/2753-unable-to-rebase-unapproved-merge-request.yml

+---
+title: allow rebase for unapproved merge requests
+merge_request:
+author:

spec/controllers/projects/merge_requests_controller_ee_spec.rb

@@ -371,12 +371,12 @@ describe Projects::MergeRequestsController do
     context 'approvals pending' do
       let(:project) { create(:project, approvals_before_merge: 1) }
 
-      it 'returns 404' do
-        expect_rebase_worker.never
+      it 'returns 200' do
+        expect_rebase_worker
 
         post_rebase
 
-        expect(response.status).to eq(404)
+        expect(response.status).to eq(200)
       end
     end