contrib/python-hook-examples.py

revlog: add a fast path for "ambiguous identifier"

Before fd1bb7c, if the C index.partialmatch raises RevlogError, the Python
code raises "ambiguous identifier" error immediately, which is efficient.

fd1bb7c took hidden revisions into consideration and forced the slow path
enumerating the changelog to double-check hidden revisions. But it's not
necessary if we know the revlog has no hidden revisions.

This patch adds back the fast path for unfiltered revlogs.

'''
Examples of useful python hooks for Mercurial.
'''
from __future__ import absolute_import
from mercurial import (
    patch,
    util,
)

def diffstat(ui, repo, **kwargs):
    '''Example usage:

    [hooks]
    commit.diffstat = python:/path/to/this/file.py:diffstat
    changegroup.diffstat = python:/path/to/this/file.py:diffstat
    '''
    if kwargs.get('parent2'):
        return
    node = kwargs['node']
    first = repo[node].p1().node()
    if 'url' in kwargs:
        last = repo['tip'].node()
    else:
        last = node
    diff = patch.diff(repo, first, last)
    ui.write(patch.diffstat(util.iterlines(diff)))