view mercurial/repo.py @ 16124:0e0060bf2f44 stable

patch: fuzz more aggressively to match patch(1) behaviour

The previous code was assuming a default context of 3 lines. When fuzzing, it
would take this value in account to reduce the amount of removed line from
hunks top or bottom. For instance, if a hunk has only 2 lines of bottom
context, fuzzing with fuzz=1 would do nothing and with fuzz=2 it would remove
one of those lines. A hunk with one line of bottom context could not be fuzzed
at all.  patch(1) has apparently no such restrictions and takes the fuzz level
at face value.

- test-import.t: fuzz/offset changes at the beginning of file are explained by
  the new fuzzing behaviour and match patch(1) ones. Patching locations are
  different but those of my patch(1) do not make a lot of sense right now
  (patched output are the same)

- test-import-bypass.t: more agressive fuzzing makes a patching supposed to
  fail because of context, succeed. Change the diff to avoid this.

- test-mq-merge.t: more agressive fuzzing would allow the merged patch to apply
  with fuzz, but fortunately we disallow this behaviour. The new output is
  kept.

I have not enough experience with patch(1) fuzzing to know whether aligning our
implementation on it is a good or bad idea. Until now, it has been the
implementation reference. For instance, "qpush" tolerates fuzz (test-mq-merge.t
runs the special case of pushing merge revisions where fuzzing is forbidden).

# repo.py - repository base classes for mercurial
#
# Copyright 2005, 2006 Matt Mackall <[e-mail]>
# Copyright 2006 Vadim Gelfer <[e-mail]>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

from i18n import _
import error

class repository(object):
    def capable(self, name):
        '''tell whether repo supports named capability.
        return False if not supported.
        if boolean capability, return True.
        if string capability, return string.'''
        if name in self.capabilities:
            return True
        name_eq = name + '='
        for cap in self.capabilities:
            if cap.startswith(name_eq):
                return cap[len(name_eq):]
        return False

    def requirecap(self, name, purpose):
        '''raise an exception if the given capability is not present'''
        if not self.capable(name):
            raise error.CapabilityError(
                _('cannot %s; remote repository does not '
                  'support the %r capability') % (purpose, name))

    def local(self):
        return False

    def cancopy(self):
        return self.local()

    def close(self):
        pass