revlog: adapt the `reading` check for `unionrepo`
We cannot just rely on the length check for the `unionrepo` as the local revlog
might be empty while the other revlog contains data. In addition, we need to
also open the second revlog for reading when needed.
'''
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.changelog.tip()
else:
last = node
diff = patch.diff(repo, first, last)
ui.write(patch.diffstat(util.iterlines(diff)))