dirs: fix out-of-bounds access in Py3
The hack for mutating Python's variable-length integers that was
ported to py3 in
cb3048746dae (dirs: port PyInt code to work on Python
3, 2016-10-08) was reading from ob_digit[1] instead of ob_digit[0] for
some reason. Space for ob_digit[1] would only be allocated for
integers larger than 30 bits, so we ended up writing to unallocated
memory. Also, we would write an integer that's 2^30 times too large,
so we would never free these integers.
Found by AddressSanitizer.
Differential Revision: https://phab.mercurial-scm.org/D7597
# automv.py
#
# Copyright 2013-2016 Facebook, Inc.
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
"""check for unrecorded moves at commit time (EXPERIMENTAL)
This extension checks at commit/amend time if any of the committed files
comes from an unrecorded mv.
The threshold at which a file is considered a move can be set with the
``automv.similarity`` config option. This option takes a percentage between 0
(disabled) and 100 (files must be identical), the default is 95.
"""
# Using 95 as a default similarity is based on an analysis of the mercurial
# repositories of the cpython, mozilla-central & mercurial repositories, as
# well as 2 very large facebook repositories. At 95 50% of all potential
# missed moves would be caught, as well as correspond with 87% of all
# explicitly marked moves. Together, 80% of moved files are 95% similar or
# more.
#
# See http://markmail.org/thread/5pxnljesvufvom57 for context.
from __future__ import absolute_import
from mercurial.i18n import _
from mercurial import (
commands,
copies,
error,
extensions,
pycompat,
registrar,
scmutil,
similar,
)
configtable = {}
configitem = registrar.configitem(configtable)
configitem(
b'automv', b'similarity', default=95,
)
def extsetup(ui):
entry = extensions.wrapcommand(commands.table, b'commit', mvcheck)
entry[1].append(
(b'', b'no-automv', None, _(b'disable automatic file move detection'))
)
def mvcheck(orig, ui, repo, *pats, **opts):
"""Hook to check for moves at commit time"""
opts = pycompat.byteskwargs(opts)
renames = None
disabled = opts.pop(b'no_automv', False)
if not disabled:
threshold = ui.configint(b'automv', b'similarity')
if not 0 <= threshold <= 100:
raise error.Abort(_(b'automv.similarity must be between 0 and 100'))
if threshold > 0:
match = scmutil.match(repo[None], pats, opts)
added, removed = _interestingfiles(repo, match)
uipathfn = scmutil.getuipathfn(repo, legacyrelativevalue=True)
renames = _findrenames(
repo, uipathfn, added, removed, threshold / 100.0
)
with repo.wlock():
if renames is not None:
scmutil._markchanges(repo, (), (), renames)
return orig(ui, repo, *pats, **pycompat.strkwargs(opts))
def _interestingfiles(repo, matcher):
"""Find what files were added or removed in this commit.
Returns a tuple of two lists: (added, removed). Only files not *already*
marked as moved are included in the added list.
"""
stat = repo.status(match=matcher)
added = stat.added
removed = stat.removed
copy = copies.pathcopies(repo[b'.'], repo[None], matcher)
# remove the copy files for which we already have copy info
added = [f for f in added if f not in copy]
return added, removed
def _findrenames(repo, uipathfn, added, removed, similarity):
"""Find what files in added are really moved files.
Any file named in removed that is at least similarity% similar to a file
in added is seen as a rename.
"""
renames = {}
if similarity > 0:
for src, dst, score in similar.findrenames(
repo, added, removed, similarity
):
if repo.ui.verbose:
repo.ui.status(
_(b'detected move of %s as %s (%d%% similar)\n')
% (uipathfn(src), uipathfn(dst), score * 100)
)
renames[dst] = src
if renames:
repo.ui.status(_(b'detected move of %d files\n') % len(renames))
return renames