hgweb: descend empty directories in web view When a manifest has a series of directories with nothing in them but a single directory, displaying the entire chain of empty directories allows for navigation down to the first non-empty directory with a single click. Because Java links package hierarchy to directory hierarchy, and because Java conventions include at least three empty directories at the top of this hierarchy, descending down empty directories is very common in Java web tools.

"""
node.py - basic nodeid manipulation for mercurial

Copyright 2005, 2006 Matt Mackall <mpm@selenic.com>

This software may be used and distributed according to the terms
of the GNU General Public License, incorporated herein by reference.
"""

import binascii

nullrev = -1
nullid = "\0" * 20

# This ugly style has a noticeable effect in manifest parsing
hex = binascii.hexlify
bin = binascii.unhexlify

def short(node):
    return hex(node[:6])