filemerge: remove `uselocalpath` argument from `_maketempfiles()` The `localpath` argument is unused if `uselocalpath` is false, so we can use `None` as a sentinel value for the variable instead and remove extra `uselocalpath` argument. That's not much of a win, but it's a small step towards further improvements. Differential Revision: https://phab.mercurial-scm.org/D12189

# extension to emulate interrupting filemerge._filemerge

from __future__ import absolute_import

from mercurial import (
    error,
    extensions,
    filemerge,
)


def failfilemerge(*args, **kwargs):
    raise error.Abort(b"^C")


def extsetup(ui):
    extensions.wrapfunction(filemerge, 'filemerge', failfilemerge)