contrib/python-hook-examples.py

mergetools: refine vimdiff warning message

We explicitly redraw before echoing the message so that it simply
displays at the bottom of the window. Also simplifies the message
printing by using 'echomsg' (which uses 'echohl' internally) and adds
the names of the software involved for improved Googleability.

'''
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)))