tests/hgweberror.py

uncommit: add config option to keep commit by default

We have a Google-internal extension that keeps track of "review units"
(like Phabricator reviews, or Gerrit's Change-Id). This information is
stored outside of the commit. It is updated with rewrites. Every now
and then we get reports from users who are confused because `hg
uncommit` lost track of their review. Keeping the empty commit by
default would reduce this confusion. It may also cause confusion about
the empty commit. This patch adds a config option that lets us easily
test both behaviors on our users.

Differential Revision: https://phab.mercurial-scm.org/D5970

# A dummy extension that installs an hgweb command that throws an Exception.

from __future__ import absolute_import

from mercurial.hgweb import (
    webcommands,
)

def raiseerror(web):
    '''Dummy web command that raises an uncaught Exception.'''

    # Simulate an error after partial response.
    if b'partialresponse' in web.req.qsparams:
        web.res.status = b'200 Script output follows'
        web.res.headers[b'Content-Type'] = b'text/plain'
        web.res.setbodywillwrite()
        list(web.res.sendresponse())
        web.res.getbodyfile().write(b'partial content\n')

    raise AttributeError('I am an uncaught error!')

def extsetup(ui):
    setattr(webcommands, 'raiseerror', raiseerror)
    webcommands.__all__.append(b'raiseerror')