rebase: turn rebaseskipobsolete on by default
Consider the following use case. User has a set of commits he wants to rebase
onto some destination. Some of the commits in the set are already rebased
and their new versions are now among the ancestors of destination. Traditional
rebase behavior would make the rebase and effectively try to apply older
versions of these commits on top of newer versions, like this:
a` --> b --> a`
(where both 'a`' and 'a``' are rebased versions of 'a')
This is not desired since 'b' might have made changes to 'a`' which can now
result in merge conflicts. We can avoid these merge conflicts since we know
that 'a``' is an older version of 'a`', so we don't even need to put it on top
of 'b'. Rebaseskipobsolete allows us to do exactly that.
Another undesired effect of a pure rebase is that now 'a`' and 'a``' are both
successors to 'a' which is a divergence. We don't want that and not rebasing
'a' the second time allows to avoid it.
This was not enabled by default initially because we wanted to have some more
experience with it. After months of painless usages in multiple places, we are
confident enough to turn it on my default.
from __future__ import absolute_import
import errno
import os
import posixpath
import stat
from .i18n import _
from . import (
encoding,
error,
util,
)
def _lowerclean(s):
return encoding.hfsignoreclean(s.lower())
class pathauditor(object):
'''ensure that a filesystem path contains no banned components.
the following properties of a path are checked:
- ends with a directory separator
- under top-level .hg
- starts at the root of a windows drive
- contains ".."
More check are also done about the file system states:
- traverses a symlink (e.g. a/symlink_here/b)
- inside a nested repository (a callback can be used to approve
some nested repositories, e.g., subrepositories)
The file system checks are only done when 'realfs' is set to True (the
default). They should be disable then we are auditing path for operation on
stored history.
'''
def __init__(self, root, callback=None, realfs=True):
self.audited = set()
self.auditeddir = set()
self.root = root
self._realfs = realfs
self.callback = callback
if os.path.lexists(root) and not util.checkcase(root):
self.normcase = util.normcase
else:
self.normcase = lambda x: x
def __call__(self, path):
'''Check the relative path.
path may contain a pattern (e.g. foodir/**.txt)'''
path = util.localpath(path)
normpath = self.normcase(path)
if normpath in self.audited:
return
# AIX ignores "/" at end of path, others raise EISDIR.
if util.endswithsep(path):
raise error.Abort(_("path ends in directory separator: %s") % path)
parts = util.splitpath(path)
if (os.path.splitdrive(path)[0]
or _lowerclean(parts[0]) in ('.hg', '.hg.', '')
or os.pardir in parts):
raise error.Abort(_("path contains illegal component: %s") % path)
# Windows shortname aliases
for p in parts:
if "~" in p:
first, last = p.split("~", 1)
if last.isdigit() and first.upper() in ["HG", "HG8B6C"]:
raise error.Abort(_("path contains illegal component: %s")
% path)
if '.hg' in _lowerclean(path):
lparts = [_lowerclean(p.lower()) for p in parts]
for p in '.hg', '.hg.':
if p in lparts[1:]:
pos = lparts.index(p)
base = os.path.join(*parts[:pos])
raise error.Abort(_("path '%s' is inside nested repo %r")
% (path, base))
normparts = util.splitpath(normpath)
assert len(parts) == len(normparts)
parts.pop()
normparts.pop()
prefixes = []
# It's important that we check the path parts starting from the root.
# This means we won't accidentaly traverse a symlink into some other
# filesystem (which is potentially expensive to access).
for i in range(len(parts)):
prefix = os.sep.join(parts[:i + 1])
normprefix = os.sep.join(normparts[:i + 1])
if normprefix in self.auditeddir:
continue
if self._realfs:
self._checkfs(prefix, path)
prefixes.append(normprefix)
self.audited.add(normpath)
# only add prefixes to the cache after checking everything: we don't
# want to add "foo/bar/baz" before checking if there's a "foo/.hg"
self.auditeddir.update(prefixes)
def _checkfs(self, prefix, path):
"""raise exception if a file system backed check fails"""
curpath = os.path.join(self.root, prefix)
try:
st = os.lstat(curpath)
except OSError as err:
# EINVAL can be raised as invalid path syntax under win32.
# They must be ignored for patterns can be checked too.
if err.errno not in (errno.ENOENT, errno.ENOTDIR, errno.EINVAL):
raise
else:
if stat.S_ISLNK(st.st_mode):
msg = _('path %r traverses symbolic link %r') % (path, prefix)
raise error.Abort(msg)
elif (stat.S_ISDIR(st.st_mode) and
os.path.isdir(os.path.join(curpath, '.hg'))):
if not self.callback or not self.callback(curpath):
msg = _("path '%s' is inside nested repo %r")
raise error.Abort(msg % (path, prefix))
def check(self, path):
try:
self(path)
return True
except (OSError, error.Abort):
return False
def canonpath(root, cwd, myname, auditor=None):
'''return the canonical path of myname, given cwd and root'''
if util.endswithsep(root):
rootsep = root
else:
rootsep = root + os.sep
name = myname
if not os.path.isabs(name):
name = os.path.join(root, cwd, name)
name = os.path.normpath(name)
if auditor is None:
auditor = pathauditor(root)
if name != rootsep and name.startswith(rootsep):
name = name[len(rootsep):]
auditor(name)
return util.pconvert(name)
elif name == root:
return ''
else:
# Determine whether `name' is in the hierarchy at or beneath `root',
# by iterating name=dirname(name) until that causes no change (can't
# check name == '/', because that doesn't work on windows). The list
# `rel' holds the reversed list of components making up the relative
# file name we want.
rel = []
while True:
try:
s = util.samefile(name, root)
except OSError:
s = False
if s:
if not rel:
# name was actually the same as root (maybe a symlink)
return ''
rel.reverse()
name = os.path.join(*rel)
auditor(name)
return util.pconvert(name)
dirname, basename = util.split(name)
rel.append(basename)
if dirname == name:
break
name = dirname
# A common mistake is to use -R, but specify a file relative to the repo
# instead of cwd. Detect that case, and provide a hint to the user.
hint = None
try:
if cwd != root:
canonpath(root, root, myname, auditor)
hint = (_("consider using '--cwd %s'")
% os.path.relpath(root, cwd))
except error.Abort:
pass
raise error.Abort(_("%s not under root '%s'") % (myname, root),
hint=hint)
def normasprefix(path):
'''normalize the specified path as path prefix
Returned value can be used safely for "p.startswith(prefix)",
"p[len(prefix):]", and so on.
For efficiency, this expects "path" argument to be already
normalized by "os.path.normpath", "os.path.realpath", and so on.
See also issue3033 for detail about need of this function.
>>> normasprefix('/foo/bar').replace(os.sep, '/')
'/foo/bar/'
>>> normasprefix('/').replace(os.sep, '/')
'/'
'''
d, p = os.path.splitdrive(path)
if len(p) != len(os.sep):
return path + os.sep
else:
return path
# forward two methods from posixpath that do what we need, but we'd
# rather not let our internals know that we're thinking in posix terms
# - instead we'll let them be oblivious.
join = posixpath.join
dirname = posixpath.dirname