Fix Rebasing not working with Merge Requests

app/services/merge_requests/working_copy_base_service.rb

@@ -49,7 +49,11 @@ module MergeRequests
     end
 
     def git_env
-      { 'GL_ID' => Gitlab::GlId.gl_id(current_user), 'GL_PROTOCOL' => 'web' }
+      {
+        'GL_ID' => Gitlab::GlId.gl_id(current_user),
+        'GL_PROTOCOL' => 'web',
+        'GL_REPOSITORY'=> Gitlab::GlRepository.gl_repository(project, false),
+      }
     end
 
     # Don't try to print expensive instance variables.

changelogs/unreleased-ee/fix_rebase_feature.yml

+---
+title: Fix Rebasing not working with Merge Requests
+merge_request:
+author:

spec/services/merge_requests/rebase_service_spec.rb

@@ -40,6 +40,21 @@ describe MergeRequests::RebaseService do
         expect(head_commit.committer_email).to eq(user.email)
         expect(head_commit.committer_name).to eq(user.name)
       end
+
+      context 'git commands' do
+        let(:service) { described_class.new(project, user, {}) }
+
+        it 'sets GL_REPOSITORY env variable when calling git commands' do
+          expect_any_instance_of(described_class)
+            .to receive(:run_git_command).exactly(4).with(
+              anything,
+              anything,
+              hash_including('GL_REPOSITORY'),
+              anything)
+
+          service.execute(merge_request)
+        end
+      end
     end
   end
 end