contrib/python-hook-examples.py

cleanup: fix some latent open(path).read() et al calls we previously missed

This pattern was banned by check-code way back in 1b4b82063ce2 (may of
2011), but due to a regular expression rewriting bug in check-code
these particular callsites were never detected. Python 3.7 caught the
bug, which then exposed these errors.

Differential Revision: https://phab.mercurial-scm.org/D2863

'''
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)))