tests/failfilemerge.py

exchange: create transaction for bundle1 unbundling earlier

changegroup.apply() currently creates a transation if there isn't
already one. Having the callers of that method pass in an existing
transaction seems a little cleaner. To do that, we need to make sure
all callers have a transaction. Since the transaction name is used as
a hook argument (HG_TXNNAME), we need to match the name from
changegroup.apply().

# extension to emulate interrupting filemerge._filemerge

from __future__ import absolute_import

from mercurial import (
    error,
    extensions,
    filemerge,
)

def failfilemerge(filemergefn,
                  premerge, repo, mynode, orig, fcd, fco, fca, labels=None):
    raise error.Abort("^C")
    return filemergefn(premerge, repo, mynode, orig, fcd, fco, fca, labels)

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