contrib/python-hook-examples.py

subrepo: fix merging of already merged subrepos (issue1986)

This fixes a bug seen when merging a main repo which contains a subrepo when
both repos have been merged before. Each repo (main and sub) has two
branches, both of which have been merged before.

In a subrepo, if the revision to merge to is an ancestor of the current rev,
then the merge should be a noop.

Test provided by Steve Losh.

'''
Examples of useful python hooks for Mercurial.
'''
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].parents()[0].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)))