view mercurial/extensions.py @ 5042:f191bc3916f7

merge: do early copy to deal with issue636

Without copies/renames, merges source names are 1:1 with their
targets. Copies and renames introduce the possibility that there will
be two merges with the same input but different output. By doing the
copy to the destination name before the merge, the actual merge
becomes 1:1 again, and no source is the input to two different merges.

- add a preliminary scan to applyupdates to do copies
- for the merge action, pass the old name (for finding ancestors) and
  the new name (for input to the merge) to filemerge
- eliminate the old post-merge copy
- lookup file contents from new name in filemerge
- pass new name to external merge helper
- report merge failure at new name
- add a test

# extensions.py - extension handling for mercurial
#
# Copyright 2005-2007 Matt Mackall <[e-mail]>
#
# This software may be used and distributed according to the terms
# of the GNU General Public License, incorporated herein by reference.

import imp, os
import commands, hg, util, sys
from i18n import _

_extensions = {}

def find(name):
    '''return module with given extension name'''
    try:
        return _extensions[name]
    except KeyError:
        for k, v in _extensions.iteritems():
            if k.endswith('.' + name) or k.endswith('/' + name):
                return v
        raise KeyError(name)

def load(ui, name, path):
    if name in _extensions:
        return
    if path:
        # the module will be loaded in sys.modules
        # choose an unique name so that it doesn't
        # conflicts with other modules
        module_name = "hgext_%s" % name.replace('.', '_')
        if os.path.isdir(path):
            # module/__init__.py style
            d, f = os.path.split(path)
            fd, fpath, desc = imp.find_module(f, [d])
            mod = imp.load_module(module_name, fd, fpath, desc)
        else:
            mod = imp.load_source(module_name, path)
    else:
        def importh(name):
            mod = __import__(name)
            components = name.split('.')
            for comp in components[1:]:
                mod = getattr(mod, comp)
            return mod
        try:
            mod = importh("hgext.%s" % name)
        except ImportError:
            mod = importh(name)
    _extensions[name] = mod

    uisetup = getattr(mod, 'uisetup', None)
    if uisetup:
        uisetup(ui)
    reposetup = getattr(mod, 'reposetup', None)
    if reposetup:
        hg.repo_setup_hooks.append(reposetup)
    cmdtable = getattr(mod, 'cmdtable', {})
    overrides = [cmd for cmd in cmdtable if cmd in commands.table]
    if overrides:
        ui.warn(_("extension '%s' overrides commands: %s\n")
                % (name, " ".join(overrides)))
    commands.table.update(cmdtable)

def loadall(ui):
    result = ui.configitems("extensions")
    for i, (name, path) in enumerate(result):
        if path:
            path = os.path.expanduser(path)
        try:
            load(ui, name, path)
        except (util.SignalInterrupt, KeyboardInterrupt):
            raise
        except Exception, inst:
            ui.warn(_("*** failed to import extension %s: %s\n") %
                    (name, inst))
            if ui.print_exc():
                return 1