filemerge: make the 'local' path match the format that 'base' and 'other' use
If we pass a separate '$output' arg to the merge tool, we produce four files:
local, base, other, and output. In this situation, 'output' will be the
original filename, 'base' and 'other' are temporary files, and previously
'local' would be the backup file (so if 'output' was foo.txt, 'local' would be
foo.txt.orig).
This change makes it so that 'local' follows the same pattern as 'base' and
'other' - it will be a temporary file either in the
`experimental.mergetempdirprefix`-controlled directory with a name like
foo~local.txt, or in the normal system-wide temp dir with a name like
foo~local.RaNd0m.txt.
For the cases where the merge tool does not use an '$output' arg, 'local' is
still the destination filename, and 'base' and 'other' are unchanged.
The hope is that this is much easier for people to reason about; rather than
having a tool like Meld pop up with three panes, one of them with the filename
"foo.txt.orig", one with the filename "foo.txt", and one with
"foo~other.StuFf2.txt", we can (when the merge temp dir stuff is enabled) make
it show up as "foo~local.txt", "foo.txt" and "foo~other.txt", respectively.
This also opens the door to future customization, such as getting the
operation-provided labels and a hash prefix into the filenames (so we see
something like "foo~dest.abc123", "foo.txt", and "foo~src.d4e5f6").
Differential Revision: https://phab.mercurial-scm.org/D2889
# policy.py - module policy logic for Mercurial.
#
# Copyright 2015 Gregory Szorc <gregory.szorc@gmail.com>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
from __future__ import absolute_import
import os
import sys
# Rules for how modules can be loaded. Values are:
#
# c - require C extensions
# allow - allow pure Python implementation when C loading fails
# cffi - required cffi versions (implemented within pure module)
# cffi-allow - allow pure Python implementation if cffi version is missing
# py - only load pure Python modules
#
# By default, fall back to the pure modules so the in-place build can
# run without recompiling the C extensions. This will be overridden by
# __modulepolicy__ generated by setup.py.
policy = b'allow'
_packageprefs = {
# policy: (versioned package, pure package)
b'c': (r'cext', None),
b'allow': (r'cext', r'pure'),
b'cffi': (r'cffi', None),
b'cffi-allow': (r'cffi', r'pure'),
b'py': (None, r'pure'),
}
try:
from . import __modulepolicy__
policy = __modulepolicy__.modulepolicy
except ImportError:
pass
# PyPy doesn't load C extensions.
#
# The canonical way to do this is to test platform.python_implementation().
# But we don't import platform and don't bloat for it here.
if r'__pypy__' in sys.builtin_module_names:
policy = b'cffi'
# Environment variable can always force settings.
if sys.version_info[0] >= 3:
if r'HGMODULEPOLICY' in os.environ:
policy = os.environ[r'HGMODULEPOLICY'].encode(r'utf-8')
else:
policy = os.environ.get(r'HGMODULEPOLICY', policy)
def _importfrom(pkgname, modname):
# from .<pkgname> import <modname> (where . is looked through this module)
fakelocals = {}
pkg = __import__(pkgname, globals(), fakelocals, [modname], level=1)
try:
fakelocals[modname] = mod = getattr(pkg, modname)
except AttributeError:
raise ImportError(r'cannot import name %s' % modname)
# force import; fakelocals[modname] may be replaced with the real module
getattr(mod, r'__doc__', None)
return fakelocals[modname]
# keep in sync with "version" in C modules
_cextversions = {
(r'cext', r'base85'): 1,
(r'cext', r'bdiff'): 3,
(r'cext', r'diffhelpers'): 1,
(r'cext', r'mpatch'): 1,
(r'cext', r'osutil'): 4,
(r'cext', r'parsers'): 4,
}
# map import request to other package or module
_modredirects = {
(r'cext', r'charencode'): (r'cext', r'parsers'),
(r'cffi', r'base85'): (r'pure', r'base85'),
(r'cffi', r'charencode'): (r'pure', r'charencode'),
(r'cffi', r'diffhelpers'): (r'pure', r'diffhelpers'),
(r'cffi', r'parsers'): (r'pure', r'parsers'),
}
def _checkmod(pkgname, modname, mod):
expected = _cextversions.get((pkgname, modname))
actual = getattr(mod, r'version', None)
if actual != expected:
raise ImportError(r'cannot import module %s.%s '
r'(expected version: %d, actual: %r)'
% (pkgname, modname, expected, actual))
def importmod(modname):
"""Import module according to policy and check API version"""
try:
verpkg, purepkg = _packageprefs[policy]
except KeyError:
raise ImportError(r'invalid HGMODULEPOLICY %r' % policy)
assert verpkg or purepkg
if verpkg:
pn, mn = _modredirects.get((verpkg, modname), (verpkg, modname))
try:
mod = _importfrom(pn, mn)
if pn == verpkg:
_checkmod(pn, mn, mod)
return mod
except ImportError:
if not purepkg:
raise
pn, mn = _modredirects.get((purepkg, modname), (purepkg, modname))
return _importfrom(pn, mn)