* 36089-handle-ref-failure-better:
  Skip creating the merge request if repo is empty
  Just use repository would fix the test
  Since now fetch_ref is reliable, we could just rely on it
  Just use the repo. Not sure why master could pass
  Fix more tests
  Don't try to create diffs if one of the branch is missing
  Try to show exception information in the test
  Introduce MergeRequest#write_ref and Repository#write_ref
  Avoid ambiguity, which happened in a single test run
  Just detect exit status rather than check ref
  Fix some tests and report the error message
  Fake out Repository#fetch_ref for merge request if
  Detect if we didn't create the ref sooner