contrib/python-hook-examples.py

revlog: make sure we never use sparserevlog without general delta (issue6056)

We are getting user report where the delta code tries to use `sparse-revlog`
logic on repository where `generaldelta` is disabled. This can't work so we
ensure the two booleans have a consistent value.

Creating this kind of repository is not expected to be possible the current bug
report point at a clonebundle related bug that is still to be properly isolated
(Yuya Nishihara seems to a have done it).

Corrupting a repository to reproduce the issue is possible. A test using this
method is included in this fix.

'''
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)))