view tests/hgweberror.py @ 40131:535fc8a22365 stable

lfs: avoid a potential variable reference before assignment error in cmdserver

A coworker hit this once yesterday when pulling in thg (a retry worked), and
then I hit it with strip after a pull.  I had a difficult time recreating a test
for this (at least one of the tricks was to not use '-R', which seems to cause
reposetup() to be called for each command), so I'm not sure how large of a
window there actually is for this.  Calling reposetup() *after* the requirement
is added will skip the hook entirely.

The other issue I had was adding a couple `ui.status()` lines around the check
that installs the hook.  On Windows, the cmdserver process ballooned to 1.6GB
and hung.  Changing that to `ui.warn()` avoided the hang.  It also hung on
macOS, but without the large memory usage.

# 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 '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('raiseerror')