mercurial/stack.py

scmutil: make shortest() respect disambiguation revset

The previous patch would let you use a shorter prefix if the prefix is
unique within a configured revset. However, that's not very useful if
there's no simple way of knowing what that shorter prefix is. This
patch adapts the shortest() template function to use the shorter
prefixes for nodes in the configured revset.

This is currently extremely slow, because it calculates the revset for
each call to shortest(). To make this faster, the next patch will
start caching the revset instance.  Ideally we'd cache a prefix tree
instance instead.

Differential Revision: https://phab.mercurial-scm.org/D4038

# stack.py - Mercurial functions for stack definition
#
#  Copyright Matt Mackall <[e-mail]> and other
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

from __future__ import absolute_import

from . import (
    revsetlang,
    scmutil,
)

def getstack(repo, rev=None):
    """return a sorted smartrev of the stack containing either rev if it is
    not None or the current working directory parent.

    The stack will always contain all drafts changesets which are ancestors to
    the revision and are not merges.
    """
    if rev is None:
        rev = '.'

    revspec = 'reverse(only(%s) and not public() and not ::merge())'
    revset = revsetlang.formatspec(revspec, rev)
    revisions = scmutil.revrange(repo, [revset])
    revisions.sort()
    return revisions