merge: fast-forward merge with descendant
issue2538 gives a case where a changeset is merged with its child (which is on
another branch), and to my surprise the result is a real merge with two
parents, not just a "fast forward" "merge" with only the child as parent.
That is essentially the same as issue619.
Is the existing behaviour as intended and correct?
Or is the following fix correct?
Some extra "created new head" pops up with this fix, but it seems to me like
they could be considered correct. The old branch head has been superseeded by
changes on the other branch, and when the changes on the other branch is merged
back to the branch it will introduce a new head not directly related to the
previous branch head.
(I guess the intention with existing behaviour could be to ensure that the
changesets on the branch are directly connected and that no new heads pops up
on merges.)
# hook.py - hook support for mercurial
#
# Copyright 2007 Matt Mackall <mpm@selenic.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 i18n import _
import os, sys
import extensions, util
def _pythonhook(ui, repo, name, hname, funcname, args, throw):
'''call python hook. hook is callable object, looked up as
name in python module. if callable returns "true", hook
fails, else passes. if hook raises exception, treated as
hook failure. exception propagates if throw is "true".
reason for "true" meaning "hook failed" is so that
unmodified commands (e.g. mercurial.commands.update) can
be run as hooks without wrappers to convert return values.'''
ui.note(_("calling hook %s: %s\n") % (hname, funcname))
obj = funcname
if not hasattr(obj, '__call__'):
d = funcname.rfind('.')
if d == -1:
raise util.Abort(_('%s hook is invalid ("%s" not in '
'a module)') % (hname, funcname))
modname = funcname[:d]
oldpaths = sys.path
if hasattr(sys, "frozen"):
# binary installs require sys.path manipulation
modpath, modfile = os.path.split(modname)
if modpath and modfile:
sys.path = sys.path[:] + [modpath]
modname = modfile
try:
obj = __import__(modname)
except ImportError:
e1 = sys.exc_type, sys.exc_value, sys.exc_traceback
try:
# extensions are loaded with hgext_ prefix
obj = __import__("hgext_%s" % modname)
except ImportError:
e2 = sys.exc_type, sys.exc_value, sys.exc_traceback
if ui.tracebackflag:
ui.warn(_('exception from first failed import attempt:\n'))
ui.traceback(e1)
if ui.tracebackflag:
ui.warn(_('exception from second failed import attempt:\n'))
ui.traceback(e2)
raise util.Abort(_('%s hook is invalid '
'(import of "%s" failed)') %
(hname, modname))
sys.path = oldpaths
try:
for p in funcname.split('.')[1:]:
obj = getattr(obj, p)
except AttributeError:
raise util.Abort(_('%s hook is invalid '
'("%s" is not defined)') %
(hname, funcname))
if not hasattr(obj, '__call__'):
raise util.Abort(_('%s hook is invalid '
'("%s" is not callable)') %
(hname, funcname))
try:
r = obj(ui=ui, repo=repo, hooktype=name, **args)
except KeyboardInterrupt:
raise
except Exception, exc:
if isinstance(exc, util.Abort):
ui.warn(_('error: %s hook failed: %s\n') %
(hname, exc.args[0]))
else:
ui.warn(_('error: %s hook raised an exception: '
'%s\n') % (hname, exc))
if throw:
raise
ui.traceback()
return True
if r:
if throw:
raise util.Abort(_('%s hook failed') % hname)
ui.warn(_('warning: %s hook failed\n') % hname)
return r
def _exthook(ui, repo, name, cmd, args, throw):
ui.note(_("running hook %s: %s\n") % (name, cmd))
env = {}
for k, v in args.iteritems():
if hasattr(v, '__call__'):
v = v()
env['HG_' + k.upper()] = v
if repo:
cwd = repo.root
else:
cwd = os.getcwd()
if 'HG_URL' in env and env['HG_URL'].startswith('remote:http'):
r = util.system(cmd, environ=env, cwd=cwd, out=ui)
else:
r = util.system(cmd, environ=env, cwd=cwd)
if r:
desc, r = util.explain_exit(r)
if throw:
raise util.Abort(_('%s hook %s') % (name, desc))
ui.warn(_('warning: %s hook %s\n') % (name, desc))
return r
_redirect = False
def redirect(state):
global _redirect
_redirect = state
def hook(ui, repo, name, throw=False, **args):
r = False
oldstdout = -1
if _redirect:
stdoutno = sys.__stdout__.fileno()
stderrno = sys.__stderr__.fileno()
# temporarily redirect stdout to stderr, if possible
if stdoutno >= 0 and stderrno >= 0:
oldstdout = os.dup(stdoutno)
os.dup2(stderrno, stdoutno)
try:
for hname, cmd in ui.configitems('hooks'):
if hname.split('.')[0] != name or not cmd:
continue
if hasattr(cmd, '__call__'):
r = _pythonhook(ui, repo, name, hname, cmd, args, throw) or r
elif cmd.startswith('python:'):
if cmd.count(':') >= 2:
path, cmd = cmd[7:].rsplit(':', 1)
path = util.expandpath(path)
if repo:
path = os.path.join(repo.root, path)
mod = extensions.loadpath(path, 'hghook.%s' % hname)
hookfn = getattr(mod, cmd)
else:
hookfn = cmd[7:].strip()
r = _pythonhook(ui, repo, name, hname, hookfn, args, throw) or r
else:
r = _exthook(ui, repo, hname, cmd, args, throw) or r
finally:
if _redirect and oldstdout >= 0:
os.dup2(oldstdout, stdoutno)
os.close(oldstdout)
return r