Merge branch 'mh/update-ref-errors'

Error handling in the codepaths that updates refs has been improved. * mh/update-ref-errors: lock_ref_for_update(): avoid a symref resolution lock_ref_for_update(): make error handling more uniform t1404: add more tests of update-ref error handling t1404: document function test_update_rejected t1404: remove "prefix" argument to test_update_rejected t1404: rename file to t1404-update-ref-errors.sh