view hgweb.cgi @ 41476:9b2b8794f801

hgweb: log error before attempting I/O

Previously, an uncaught exception during HTTP request serving would
attempt to send an error response then log the exception.

If an exception occurred during I/O, this exception would be
raised and the original exception wouldn't be logged.

This commit changes behavior so the original exception is logged
first, before we attempt to do anything else. This ensures the
exception is logged.

This change resulted in new tracebacks appearing in various tests.

Because tracebacks can vary between Python versions, we added a
simple script to filter the stack part of traceback lines. This
makes testing much simpler, as we don't need to glob over lines
and make lines conditional.

Differential Revision: https://phab.mercurial-scm.org/D5749

#!/usr/bin/env python
#
# An example hgweb CGI script, edit as necessary
# See also https://mercurial-scm.org/wiki/PublishingRepositories

# 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()

from mercurial import demandimport; demandimport.enable()
from mercurial.hgweb import hgweb, wsgicgi
application = hgweb(config)
wsgicgi.launch(application)