contrib/python-hook-examples.py

diffstat: properly count lines starting in '--' or '++' (issue5479)

Lines that start in '--' or '++' were previously not counted
as deletions or additions in diffstat, resulting in incorrect
addition/deletion counts.  The bug was present if the start
of the line, combined with the diff character resulted
in '---' or '+++'.

diffstatdata will now track, for each file, if it has moved
pas the header section by looking for a line beginning with
'@@'.  Once that has happened, lines beginning with '-'
or '+' will be counted for deletions and additions.  Once a
line beginning with 'diff' is found, the process starts over.

'''
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)))