tests/failfilemerge.py

merge: use labels in prompts to the user

Now that we persist the labels, we can consistently use the labels in
prompts for the user without risk of confusion. This changes a huge amount
of command output:

This means that merge prompts like:
  no tool found to merge a
  keep (l)ocal, take (o)ther, or leave (u)nresolved? u
and
  remote changed a which local deleted
  use (c)hanged version, leave (d)eleted, or leave (u)nresolved? c
become:
  no tool found to merge a
  keep (l)ocal [working copy], take (o)ther [destination], or leave (u)nresolved? u
and
  remote [source] changed a which local [dest] deleted
  use (c)hanged version, leave (d)eleted, or leave (u)nresolved? c
where "working copy" and "destination" were supplied by the command that
requested the merge as labels for conflict markers, and thus should be
human-friendly.

# 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)