tests/lockdelay.py

context: make repo[<filtered binary nodeid>] match node

If you pass in a binary nodeid of a filtered node to repo.__getitem__,
it would run through this code:

    try:
        self._node = changeid
	self._rev = repo.changelog.rev(changeid)
	return
    except error.FilteredLookupError:
        raise
    except LookupError:
         pass

However, repo.changelog.rev() would raise a FilteredLookupError, not
FilteredRepoLookupError. Instead, we would hit the "except
LookupError" and continue, trying to interpret the nodeid as a
bookmark etc. The end result would be an error like this:

  abort: unknown revision 'ddadbd7c40ef8b8ad6d0d01a7a842092fc431798'!

After this patch, it would instead be:

  abort: 00changelog.i@ddadbd7c40ef8b8ad6d0d01a7a842092fc431798: filtered node!

This only happens when we get a binary nodeid, which means it's not
string directly from the user, so it would be a programming error if
it happened. It's therefore a little hard to test (I checked
test-context.py, but it doesn't use obsmarkers).

It looks like this has been wrong ever since dc25ed84bee8 (changectx:
issue a FilteredRepoLookupError when applicable, 2014-10-15).

Differential Revision: https://phab.mercurial-scm.org/D3144

# Dummy extension that adds a delay after acquiring a lock.
#
# This extension can be used to test race conditions between lock acquisition.

from __future__ import absolute_import

import os
import time

def reposetup(ui, repo):

    class delayedlockrepo(repo.__class__):
        def lock(self):
            delay = float(os.environ.get('HGPRELOCKDELAY', '0.0'))
            if delay:
                time.sleep(delay)
            res = super(delayedlockrepo, self).lock()
            delay = float(os.environ.get('HGPOSTLOCKDELAY', '0.0'))
            if delay:
                time.sleep(delay)
            return res
    repo.__class__ = delayedlockrepo