Changeset 391 for python/trunk/Lib/posixpath.py

Timestamp:

Mar 19, 2014, 11:31:01 PM (11 years ago)

Author:

dmik

Message:

python: Merge vendor 2.7.6 to trunk.

Location:

python/trunk

Files:

• . (modified) (1 prop)
• Lib/posixpath.py (modified) (9 diffs)

python/trunk/Lib/posixpath.py

@@ -12 +12 @@
 
 import os
+import sys
 import stat
 import genericpath
 import warnings
 from genericpath import *
+
+try:
+    _unicode = unicode
+except NameError:
+    # If Python is built without Unicode support, the unicode type
+    # will not exist. Fake one.
+    class _unicode(object):
+        pass
 
 __all__ = ["normcase","isabs","join","splitdrive","split","splitext",
@@ -60 +69 @@
     """Join two or more pathname components, inserting '/' as needed.
     If any component is an absolute path, all previous path components
-    will be discarded."""
+    will be discarded.  An empty last part will result in a path that
+    ends with a separator."""
     path = a
     for b in p:
@@ -140 +150 @@
     """Test whether a path exists.  Returns True for broken symbolic links"""
     try:
-        st = os.lstat(path)
+        os.lstat(path)
     except os.error:
         return False
@@ -179 +189 @@
 def ismount(path):
     """Test whether a path is a mount point"""
+    if islink(path):
+        # A symlink can never be a mount point
+        return False
     try:
         s1 = os.lstat(path)
@@ -264 +277 @@
             return path
         userhome = pwent.pw_dir
-    userhome = userhome.rstrip('/') or userhome
-    return userhome + path[i:]
+    userhome = userhome.rstrip('/')
+    return (userhome + path[i:]) or '/'
 
 
@@ -309 +322 @@
     """Normalize path, eliminating double slashes, etc."""
     # Preserve unicode (if path is unicode)
-    slash, dot = (u'/', u'.') if isinstance(path, unicode) else ('/', '.')
+    slash, dot = (u'/', u'.') if isinstance(path, _unicode) else ('/', '.')
     if path == '':
         return dot
@@ -338 +351 @@
     """Return an absolute path."""
     if not isabs(path):
-        if isinstance(path, unicode):
+        if isinstance(path, _unicode):
             cwd = os.getcwdu()
         else:
@@ -352 +365 @@
     """Return the canonical path of the specified filename, eliminating any
 symbolic links encountered in the path."""
-    if isabs(filename):
-        bits = ['/'] + filename.split('/')[1:]
-    else:
-        bits = [''] + filename.split('/')
-
-    for i in range(2, len(bits)+1):
-        component = join(*bits[0:i])
-        # Resolve symbolic links.
-        if islink(component):
-            resolved = _resolve_link(component)
-            if resolved is None:
-                # Infinite loop -- return original component + rest of the path
-                return abspath(join(*([component] + bits[i:])))
+    path, ok = _joinrealpath('', filename, {})
+    return abspath(path)
+
+# Join two paths, normalizing ang eliminating any symbolic links
+# encountered in the second path.
+def _joinrealpath(path, rest, seen):
+    if isabs(rest):
+        rest = rest[1:]
+        path = sep
+
+    while rest:
+        name, _, rest = rest.partition(sep)
+        if not name or name == curdir:
+            # current dir
+            continue
+        if name == pardir:
+            # parent dir
+            if path:
+                path, name = split(path)
+                if name == pardir:
+                    path = join(path, pardir, pardir)
             else:
-                newpath = join(*([resolved] + bits[i:]))
-                return realpath(newpath)
-
-    return abspath(filename)
-
-
-def _resolve_link(path):
-    """Internal helper function.  Takes a path and follows symlinks
-    until we either arrive at something that isn't a symlink, or
-    encounter a path we've seen before (meaning that there's a loop).
-    """
-    paths_seen = []
-    while islink(path):
-        if path in paths_seen:
-            # Already seen this path, so we must have a symlink loop
-            return None
-        paths_seen.append(path)
-        # Resolve where the link points to
-        resolved = os.readlink(path)
-        if not isabs(resolved):
-            dir = dirname(path)
-            path = normpath(join(dir, resolved))
-        else:
-            path = normpath(resolved)
-    return path
-
-supports_unicode_filenames = False
+                path = pardir
+            continue
+        newpath = join(path, name)
+        if not islink(newpath):
+            path = newpath
+            continue
+        # Resolve the symbolic link
+        if newpath in seen:
+            # Already seen this path
+            path = seen[newpath]
+            if path is not None:
+                # use cached value
+                continue
+            # The symlink is not resolved, so we must have a symlink loop.
+            # Return already resolved part + rest of the path unchanged.
+            return join(newpath, rest), False
+        seen[newpath] = None # not resolved symlink
+        path, ok = _joinrealpath(path, os.readlink(newpath), seen)
+        if not ok:
+            return join(path, rest), False
+        seen[newpath] = path # resolved symlink
+
+    return path, True
+
+
+supports_unicode_filenames = (sys.platform == 'darwin')
 
 def relpath(path, start=curdir):
@@ -400 +420 @@
         raise ValueError("no path specified")
 
-    start_list = abspath(start).split(sep)
-    path_list = abspath(path).split(sep)
+    start_list = [x for x in abspath(start).split(sep) if x]
+    path_list = [x for x in abspath(path).split(sep) if x]
 
     # Work out how much of the filepath is shared by start and path.