pathutil: add dirname and join functions

This adds dirname and join functions to pathutil which are explicitly for
handling '/' delimited paths. The implementations are basically copy paste from
python's posix os.path.dirname and os.path.join functions.

mercurial/pathutil.py

@@ -1,189 +1,254
 import os, errno, stat
 
 import encoding
 import util
 from i18n import _
 
 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 ".."
     - 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 _lowerclean(parts[0]) in ('.hg', '.hg.', '')
             or os.pardir in parts):
             raise util.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 util.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 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
 
         # 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 util.Abort:
             pass
 
         raise util.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
+
+def join(path, *paths):
+    '''Join two or more pathname components, inserting '/' as needed.
+
+    Based on the posix os.path.join() implementation.
+
+    >>> join('foo', 'bar')
+    'foo/bar'
+    >>> join('/foo', 'bar')
+    '/foo/bar'
+    >>> join('foo', '/bar')
+    '/bar'
+    >>> join('foo', 'bar/')
+    'foo/bar/'
+    >>> join('foo', 'bar', 'gah')
+    'foo/bar/gah'
+    >>> join('foo')
+    'foo'
+    >>> join('', 'foo')
+    'foo'
+    >>> join('foo/', 'bar')
+    'foo/bar'
+    >>> join('', '', '')
+    ''
+    >>> join ('foo', '', '', 'bar')
+    'foo/bar'
+    '''
+    sep = '/'
+    if not paths:
+        path[:0] + sep #23780: Ensure compatible data type even if p is null.
+    for piece in paths:
+        if piece.startswith(sep):
+            path = piece
+        elif not path or path.endswith(sep):
+            path += piece
+        else:
+            path += sep + piece
+    return path
+
+def dirname(path):
+    '''returns the directory portion of the given path
+
+    Based on the posix os.path.split() implementation.
+
+    >>> dirname('foo')
+    ''
+    >>> dirname('foo/')
+    'foo'
+    >>> dirname('foo/bar')
+    'foo'
+    >>> dirname('/foo')
+    '/'
+    >>> dirname('/foo/bar')
+    '/foo'
+    >>> dirname('/foo//bar/poo')
+    '/foo//bar'
+    >>> dirname('/foo//bar')
+    '/foo'
+    '''
+    sep = '/'
+    i = path.rfind(sep) + 1
+    dirname = path[:i]
+    if dirname and dirname != sep * len(dirname):
+        dirname = dirname.rstrip(sep)
+    return dirname