hook: have a generic hook for transaction opening
We are adding generic hooking for all transactions. We do not really have any
useful information to include when opening the transaction but this is a
useful time to allow a hook anyway. We better let people abort transaction before
they happen than after multiple seconds/minutes of processing.
# A dummy extension that installs an hgweb command that throws an Exception.
from mercurial.hgweb import webcommands
def raiseerror(web, req, tmpl):
'''Dummy web command that raises an uncaught Exception.'''
# Simulate an error after partial response.
if 'partialresponse' in req.form:
req.respond(200, 'text/plain')
req.write('partial content\n')
raise AttributeError('I am an uncaught error!')
def extsetup(ui):
setattr(webcommands, 'raiseerror', raiseerror)
webcommands.__all__.append('raiseerror')