Index: Lib/test/test_support.py
===================================================================
--- Lib/test/test_support.py	(revision 77513)
+++ Lib/test/test_support.py	(working copy)
@@ -612,6 +612,29 @@
         sys.path[:] = self.original_value
 
 
+class TempCWD(object):
+    """Context manager to temporarily create a directory and set it as CWD.
+
+    Example:
+    with TempCWD('foo'):
+        assertEqual(os.path.basename(os.getcwd()), 'foo')
+    """
+
+    def __init__(self, dirname='tempcwd'):
+        self.dirname = os.path.join(TESTFN+'_cwd', dirname)
+        self._oldcwd = os.getcwd()
+
+    def __enter__(self):
+        if not os.path.exists(self.dirname):
+            os.makedirs(self.dirname)
+        os.chdir(self.dirname)
+        return self.dirname
+
+    def __exit__(self, exc, value, tb):
+        os.chdir(self._oldcwd)
+        rmtree(os.path.dirname(self.dirname))
+
+
 class TransientResource(object):
 
     """Raise ResourceDenied if an exception is raised while the context manager