contrib/python-hook-examples.py

tests: conditionalize an error message about unlinking a non empty directory

The message on Windows comes from win32.unlink().  It looks like os.unlink() on
posix platforms is a simple call to unlink(3), which turns into unlinkat(2).
Since there's a comment in one of the tests that the message should be improved,
I don't think it's worth adding a check in win32.unlink() to see if it's empty,
if that function is always going to fail on a directory.  (It seems like the
POSIX spec allows unlinking directories though.)

'''
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)))