contrib/python-hook-examples.py

filemerge: stop passing around 3 unused `None` values in `files` argument

Since 67cfffbfb6a0 (filemerge: eliminate most uses of tempfiles,
2017-08-31), we have used only the last entry in the `files` tuple
that gets passed around to various functions. That commit said
"Emphasize that they're unused so we can more easily remove them
later.". It's now "later".

Differential Revision: https://phab.mercurial-scm.org/D11877

'''
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.changelog.tip()
    else:
        last = node
    diff = patch.diff(repo, first, last)
    ui.write(patch.diffstat(util.iterlines(diff)))