D759: dirstate: move parents source of truth to dirstatemap

[indygreg (Gregory Szorc)]

indygreg requested changes to this revision.
indygreg added a comment.
This revision now requires changes to proceed.


  The logic here isn't readable enough that IMO we should fix it in flight.

INLINE COMMENTS

> dirstate.py:1382-1383
> +                    raise
> +            if not self._parents:
> +                self._parents = [nullid, nullid]
> +

This code doesn't read very cleanly.

The only cases where `self._parents` won't be set here are if the file exists but is empty or the file doesn't exist. I'd rather make that logic explicit and `assert self._parents` here.

Note that if the code were changed so an empty string represented both missing and empty files, the resulting code would be pretty clear via a //switch// statement against the content length.

REPOSITORY
  rHG Mercurial

REVISION DETAIL
  https://phab.mercurial-scm.org/D759

To: durham, #hg-reviewers, indygreg
Cc: indygreg, mercurial-devel