commit finds different missing files based on use_record_iter_changes=True/False

Example:

  mkdir a a/c a/d
  touch a/c/e a/d/f g
  bzr add
  bzr commit -m "all"

  rm -rf a

At the moment, if the commit code has 'use_record_iter_changes=True' this ends up with 'missing' files marked as all of a a/c a/d a/c/e a/d/f. If use_record_iter_changes=False, then it only finds 'a' as missing.

I have an open guess that if use_record_iter_changes is False, then the delta is actually invalid to use for update_basis_by_delta, but I don't have any proof of that yet.