D777: merge: add merge action 'pr' to rename files during update

[mbthomas (Mark Thomas)]

mbthomas added inline comments.

INLINE COMMENTS

> ryanmce wrote in merge.py:1461
> Thanks for remembering to preserve copy information!
> 
> Did you test with transitive renames? Something like:
> 
> I rename `a` -> `b`
> I run `hg update @` and `@` has a new directory `b`
> Then `b` gets renamed to `b.blahblah`
> Does this properly cover the rename from `a` to `b.blahblah` after that?

I had tested transitive renames after update, but not before.  I'll fix it up and add a test.

REPOSITORY
  rHG Mercurial

REVISION DETAIL
  https://phab.mercurial-scm.org/D777

To: mbthomas, #hg-reviewers
Cc: ryanmce, mercurial-devel