tests/readlink.py

filemerge: put temporary files in single temp dir by default

The feature introduced in D2888 seems like a pure improvement to
me. It makes the names' of temporary file easier to read. Let's have
it always enabled.

I also removed the config option for the path prefix because it
doesn't seem useful. I asked Kyle (the author of the feature) about it
and he couldn't think of a reason to keep it. I suspect it was just
that we to have a config to turn it on/off while it was experimental,
so it might as well be a configurable prefix then.

Differential Revision: https://phab.mercurial-scm.org/D12171

#!/usr/bin/env python3

from __future__ import absolute_import, print_function

import errno
import os
import sys

for f in sys.argv[1:]:
    try:
        print(f, '->', os.readlink(f))
    except OSError as err:
        if err.errno != errno.EINVAL:
            raise
        print(f, '->', f, 'not a symlink')

sys.exit(0)