revset: prevent crash caused by empty group expression while optimizing "and"
An empty group expression "()" generates None in AST, so the optimizer have
to test it before destructuring a tuple. The error message, "missing argument",
is somewhat obscure, but it should be better than crash.
'''
Examples of useful python hooks for Mercurial.
'''
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)))