hgweb: catch util.Abort raised by addchangegroup
Right now, if a pretxnchangegroup hook fails, we send some HTML
error message to the client and the transaction is not rolled back
(issue499).
Catching util.Abort allows us to send a decent message to the client
and for some reason makes the rollback complete.
This patch is not perfect since it doesn't fix the reason why the
transaction wasn't rolled back (maybe some circular references?).
Also, the transaction is aborted only after we've sent the response
back to the client and the "transaction aborted" message ends up in
the logs of the web server.
# hgweb/wsgicgi.py - CGI->WSGI translator
#
# Copyright 2006 Eric Hopper <hopper@omnifarious.org>
#
# This software may be used and distributed according to the terms
# of the GNU General Public License, incorporated herein by reference.
#
# This was originally copied from the public domain code at
# http://www.python.org/dev/peps/pep-0333/#the-server-gateway-side
import os, sys
from mercurial import util
def launch(application):
util.set_binary(sys.stdout)
environ = dict(os.environ.items())
environ['wsgi.input'] = sys.stdin
environ['wsgi.errors'] = sys.stderr
environ['wsgi.version'] = (1, 0)
environ['wsgi.multithread'] = False
environ['wsgi.multiprocess'] = True
environ['wsgi.run_once'] = True
if environ.get('HTTPS','off') in ('on','1'):
environ['wsgi.url_scheme'] = 'https'
else:
environ['wsgi.url_scheme'] = 'http'
headers_set = []
headers_sent = []
out = sys.stdout
def write(data):
if not headers_set:
raise AssertionError("write() before start_response()")
elif not headers_sent:
# Before the first output, send the stored headers
status, response_headers = headers_sent[:] = headers_set
out.write('Status: %s\r\n' % status)
for header in response_headers:
out.write('%s: %s\r\n' % header)
out.write('\r\n')
out.write(data)
out.flush()
def start_response(status, response_headers, exc_info=None):
if exc_info:
try:
if headers_sent:
# Re-raise original exception if headers sent
raise exc_info[0], exc_info[1], exc_info[2]
finally:
exc_info = None # avoid dangling circular ref
elif headers_set:
raise AssertionError("Headers already set!")
headers_set[:] = [status, response_headers]
return write
result = application(environ, start_response)
try:
for data in result:
if data: # don't send headers until body appears
write(data)
if not headers_sent:
write('') # send headers now if body was empty
finally:
if hasattr(result,'close'):
result.close()