tests/hgweberror.py

test-check-help: fix to work on Windows

The initial problem was `hg files` prints paths with '\', which gets removed
when piped (scanhelptopics.py failed to open 'hgext__init__.py').  Then, xargs
was invoking `hg help` with 'backout\r (esc)', which setting binary mode
prevents.

# 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, 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')