view CONTRIBUTING @ 37787:92213f6745ed

rebase: introduce support for automatically rebasing orphan changes

_destautorebase(SRC) is based on the _destrestack(SRC) revset from
fbamend. The supporting _possibledestination function is extracted
from evolve, with minor cleanups.

We've considered some alternatives here:
 * This change, but with --auto as the flag name. We're hedging our bets
   on this a little in this change so that if this ends up being the wrong
   direction we haven't burned the valauble --auto name on rebase.
 * --destination auto: I've got reservations about the discoverability of this,
   and we don't currently have a good story for a revset alias of sorts that
   changes behavior depending on the context in which it's used.
 * A "rebase presets" feature, where we could use the currently-an-error
   positional argument space for the rebase command to define presets, so that
   users could define a 'linearize' preset that specifies
   --revision='orphan()-obsolete()' and --dest=_destautoorphanrebase(SRC).

Personally, I find the third option somewhat appealing, but am
hesitant to "spend" the functionality space of positional arguments to
the rebase command. We should revisit the way we expose this
functionality sometime in the 4.7 cycle once we've had a chance to vet
the implementation of the functionality.

Differential Revision: https://phab.mercurial-scm.org/D2668

Our full contribution guidelines are in our wiki, please see:

https://www.mercurial-scm.org/wiki/ContributingChanges

If you just want a checklist to follow, you can go straight to

https://www.mercurial-scm.org/wiki/ContributingChanges#Submission_checklist

If you can't run the entire testsuite for some reason (it can be
difficult on Windows), please at least run `contrib/check-code.py` on
any files you've modified and run `python contrib/check-commit` on any
commits you've made (for example, `python contrib/check-commit
273ce12ad8f1` will report some style violations on a very old commit).