fncache: document the fact fncache is outdate at hook run time
Using 'addfinalize' to generate 'fncache' means that no pending version of the
file will be generated for the hooks. We would have to use the
'addfilegenerator' method to get such result. However the 'fncachevfs' (who
decide that a write is necessary) have no access to the transaction to register
such file generation at add time. Having the transaction accessible to the 'vfs'
is too much trouble for no benefit. This outdated 'fncache' file at hook time is
not expected to be an issue.
The previous move from 'onclose' to 'addfinalize' had no impact on this timing.
I'm documenting it now because I looked at it.
import os, errno, stat
import util
from i18n import _
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 ".."
- 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)
'''
def __init__(self, root, callback=None):
self.audited = set()
self.auditeddir = set()
self.root = root
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 util.Abort(_("path ends in directory separator: %s") % path)
parts = util.splitpath(path)
if (os.path.splitdrive(path)[0]
or parts[0].lower() in ('.hg', '.hg.', '')
or os.pardir in parts):
raise util.Abort(_("path contains illegal component: %s") % path)
if '.hg' in path.lower():
lparts = [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 util.Abort(_("path '%s' is inside nested repo %r")
% (path, base))
normparts = util.splitpath(normpath)
assert len(parts) == len(normparts)
parts.pop()
normparts.pop()
prefixes = []
while parts:
prefix = os.sep.join(parts)
normprefix = os.sep.join(normparts)
if normprefix in self.auditeddir:
break
curpath = os.path.join(self.root, prefix)
try:
st = os.lstat(curpath)
except OSError, 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):
raise util.Abort(
_('path %r traverses symbolic link %r')
% (path, prefix))
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):
raise util.Abort(_("path '%s' is inside nested "
"repo %r")
% (path, prefix))
prefixes.append(normprefix)
parts.pop()
normparts.pop()
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 check(self, path):
try:
self(path)
return True
except (OSError, util.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
raise util.Abort(_("%s not under root '%s'") % (myname, root))
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