tests/failfilemerge.py

mail: do not print(), use ui.debug() instead

Since print() can't take a bytes output, it's pretty useless in Mercurial
on Python 3. As this is a debug message, switching to ui.debug() seems fine.

# extension to emulate interupting 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)