copies: consider nullrev a common ancestor
I've seen many bugs in the git codebase that were caused by it not
having a null revision and being forced to treat root commits
differently. Mercurial has a null revision and I think it's generally
a bug to treat it differently from other commits in graph algorithms.
This effectively undoes
83cfa1baf8ad (copies: don't report copies with
unrelated branch, 2010-01-01). The test cases that that commit added
still passes. I suspect some other fix after that commit made it
unnecessary.
Differential Revision: https://phab.mercurial-scm.org/D5594
# debugshell extension
"""a python shell with repo, changelog & manifest objects"""
from __future__ import absolute_import
import code
import mercurial
import sys
from mercurial import (
demandimport,
registrar,
)
cmdtable = {}
command = registrar.command(cmdtable)
def pdb(ui, repo, msg, **opts):
objects = {
'mercurial': mercurial,
'repo': repo,
'cl': repo.changelog,
'mf': repo.manifestlog,
}
code.interact(msg, local=objects)
def ipdb(ui, repo, msg, **opts):
import IPython
cl = repo.changelog
mf = repo.manifestlog
cl, mf # use variables to appease pyflakes
IPython.embed()
@command('debugshell|dbsh', [])
def debugshell(ui, repo, **opts):
bannermsg = "loaded repo : %s\n" \
"using source: %s" % (repo.root,
mercurial.__path__[0])
pdbmap = {
'pdb' : 'code',
'ipdb' : 'IPython'
}
debugger = ui.config("ui", "debugger")
if not debugger:
debugger = 'pdb'
# if IPython doesn't exist, fallback to code.interact
try:
with demandimport.deactivated():
__import__(pdbmap[debugger])
except ImportError:
ui.warn(("%s debugger specified but %s module was not found\n")
% (debugger, pdbmap[debugger]))
debugger = 'pdb'
getattr(sys.modules[__name__], debugger)(ui, repo, bannermsg, **opts)