contrib/python-hook-examples.py

phases: check HG_PENDING strictly

Before this patch, checking HG_PENDING in phases.py might cause
unintentional reading unrelated 'phaseroots.pending' in, because it
just examines existence of HG_PENDING environment variable.

This patch uses txnutil.trypending() to check HG_PENDING strictly.

BTW, this patch may cause failure of bisect in the repository of
Mercurial itself, if examination at bisecting assumes that an external
hook can see all pending changes while nested transactions across
repositories.

This invisibility issue will be fixed by subsequent patch, which
allows HG_PENDING to refer multiple repositories.

'''
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)))