Index: Lib/os.py
===================================================================
--- Lib/os.py	(revision 41601)
+++ Lib/os.py	(working copy)
@@ -24,6 +24,7 @@
 #'
 
 import sys
+import errno
 
 _names = sys.builtin_module_names
 
@@ -147,6 +148,20 @@
 # Super directory utilities.
 # (Inspired by Eric Raymond; the doc strings are mostly his)
 
+
+def _splits(name):
+    """ Split path removing trailing separators and curdir from tail
+        
+    >>> splits('a/b/c//.')
+    'a/b', 'c'
+        
+    """
+    head, tail = name, ''
+    while head and (tail == '' or tail == curdir):
+        head, tail = path.split(head)
+    return head, tail
+
+
 def makedirs(name, mode=0777):
     """makedirs(path [, mode=0777])
 
@@ -155,16 +170,17 @@
     just the rightmost) will be created if it does not exist.  This is
     recursive.
 
-    """
-    head, tail = path.split(name)
-    if not tail:
-        head, tail = path.split(head)
-    if head and tail and not path.exists(head):
-        makedirs(head, mode)
-        if tail == curdir:           # xxx/newdir/. exists if xxx/newdir exists
-            return
-    mkdir(name, mode)
+    """        
+    head, tail = _splits(name)
+    if head:
+        try:
+            mkdir(head, mode)
+        except error, err:
+            if err.errno != errno.EEXIST:
+                makedirs(head, mode)
+    mkdir(path.join(head, tail), mode)
 
+
 def removedirs(name):
     """removedirs(path)
 
@@ -177,9 +193,7 @@
 
     """
     rmdir(name)
-    head, tail = path.split(name)
-    if not tail:
-        head, tail = path.split(head)
+    head, tail = _splits(name)
     while head and tail:
         try:
             rmdir(head)
Index: Lib/test/test_os.py
===================================================================
--- Lib/test/test_os.py	(revision 41601)
+++ Lib/test/test_os.py	(working copy)
@@ -5,6 +5,7 @@
 import os
 import unittest
 import warnings
+import shutil
 from test import test_support
 
 warnings.filterwarnings("ignore", "tempnam", RuntimeWarning, __name__)
@@ -312,38 +313,70 @@
                 os.rmdir(join(root, name))
         os.rmdir(test_support.TESTFN)
 
-class MakedirTests (unittest.TestCase):
+
+class SplitsTests(unittest.TestCase):
+
+    def test_empty(self):
+        self.assertEqual(os._splits(''), ('', ''))
+
+    def test_single_element(self):
+        self.assertEqual(os._splits('a'), ('', 'a'))
+
+    def test_curdir(self):
+        self.assertEqual(os._splits(os.curdir), ('', os.curdir))
+
+    def test_traling_seps(self):
+        path = os.path.join('a','b') + os.sep + os.sep
+        self.assertEqual(os._splits(path), ('a', 'b'))
+
+    def test_traling_curdirs(self):
+        pointless = (os.sep + os.curdir) * 3
+        path = os.path.join('a','b') + pointless
+        self.assertEqual(os._splits(path), ('a', 'b'))
+
+
+class MakedirTests(unittest.TestCase):
+    
+    base = test_support.TESTFN
+
     def setUp(self):
-        os.mkdir(test_support.TESTFN)
+        os.mkdir(self.base)
+    
+    def test_existing(self):
+        self.failUnlessRaises(OSError, os.makedirs, self.base)
 
-    def test_makedir(self):
-        base = test_support.TESTFN
-        path = os.path.join(base, 'dir1', 'dir2', 'dir3')
-        os.makedirs(path)             # Should work
-        path = os.path.join(base, 'dir1', 'dir2', 'dir3', 'dir4')
-        os.makedirs(path)
-
-        # Try paths with a '.' in them
+    def test_existing_curdir(self):
         self.failUnlessRaises(OSError, os.makedirs, os.curdir)
-        path = os.path.join(base, 'dir1', 'dir2', 'dir3', 'dir4', 'dir5', os.curdir)
-        os.makedirs(path)
-        path = os.path.join(base, 'dir1', os.curdir, 'dir2', 'dir3', 'dir4',
-                            'dir5', 'dir6')
-        os.makedirs(path)
 
+    def test_existing_pardir(self):
+        self.failUnlessRaises(OSError, os.makedirs, os.pardir)
+        self.failUnlessRaises(OSError, os.makedirs, 
+                              os.path.join(self.base, os.pardir))
 
+    def test_single(self):
+        self._test(self.base, 'dir1')
 
+    def test_multiple(self):
+        self._test(self.base, 'dir1', 'dir2', 'dir3')
+            
+    def test_curdir_leading(self):
+        self._test(os.curdir, self.base, 'dir1', 'dir2')
 
+    def test_curdir_within(self):
+        self._test(self.base, 'dir1', os.curdir, 'dir2')
+
+    def test_curdir_traling(self):     
+        self._test(self.base, 'dir1', 'dir2', os.curdir)
+                
+    def _test(self, *parts):
+        path = os.path.join(*parts)
+        os.makedirs(path)
+        self.failUnless(os.path.isdir(path),
+                        'directory %s should exists' % path)
+
     def tearDown(self):
-        path = os.path.join(test_support.TESTFN, 'dir1', 'dir2', 'dir3',
-                            'dir4', 'dir5', 'dir6')
-        # If the tests failed, the bottom-most directory ('../dir6')
-        # may not have been created, so we look for the outermost directory
-        # that exists.
-        while not os.path.exists(path) and path != test_support.TESTFN:
-            path = os.path.dirname(path)
+        shutil.rmtree(self.base, ignore_errors=True)
 
-        os.removedirs(path)
 
 class DevNullTests (unittest.TestCase):
     def test_devnull(self):
@@ -370,6 +403,7 @@
         StatAttributeTests,
         EnvironTests,
         WalkTests,
+        SplitsTests,
         MakedirTests,
         DevNullTests,
         URandomTests