contrib/hgweb.wsgi

hgweb: filter graphmod.colored() output before iterating over it

Consumers in this function use output of graphmod.colored(), but only want
items with type == CHANGESET, so let's filter it early.

This is primarily just a refactoring, but it also fixes a potential small bug
with `rows = len(tree)` (this variable is used for "Rows shown" line in
raw-graph) if there are items of other types.

# An example WSGI for use with mod_wsgi, edit as necessary
# See https://mercurial-scm.org/wiki/modwsgi for more information

# Path to repo or hgweb config to serve (see 'hg help hgweb')
config = "/path/to/repo/or/config"

# Uncomment and adjust if Mercurial is not installed system-wide
# (consult "installed modules" path from 'hg debuginstall'):
#import sys; sys.path.insert(0, "/path/to/python/lib")

# Uncomment to send python tracebacks to the browser if an error occurs:
#import cgitb; cgitb.enable()

# enable demandloading to reduce startup time
from mercurial import demandimport; demandimport.enable()

from mercurial.hgweb import hgweb
application = hgweb(config)