D2068: revlog: do not use delta for lfs revisions

[quark (Jun Wu)]

quark added inline comments.

INLINE COMMENTS

> ryanmce wrote in revlog.py:2110
> Why is this not `candelta()`?

`candelta` takes two revisions. Here there is only one revision. It's possible to pass a useless revision but that has unnecessary overhead.

`candelta` also fetches `flags`, here we already know the values `flags` so it's faster to avoid fetching it again.

REPOSITORY
  rHG Mercurial

REVISION DETAIL
  https://phab.mercurial-scm.org/D2068

To: quark, indygreg, #hg-reviewers, ryanmce
Cc: mercurial-devel