diff -r c592e5a8fa4f Doc/library/filecmp.rst
--- a/Doc/library/filecmp.rst	Tue Aug 14 21:45:25 2012 -0400
+++ b/Doc/library/filecmp.rst	Thu Aug 23 10:17:37 2012 -0700
@@ -57,7 +57,7 @@
 
    Construct a new directory comparison object, to compare the directories *a* and
    *b*. *ignore* is a list of names to ignore, and defaults to ``['RCS', 'CVS',
-   'tags']``. *hide* is a list of names to hide, and defaults to ``[os.curdir,
+   'tags', r'\.svn', r'\.hg', r'\.git', r'\.bzr', '_darcs']``. *hide* is a list of names to hide, and defaults to ``[os.curdir,
    os.pardir]``.
 
    The :class:`dircmp` class compares files by doing *shallow* comparisons
diff -r c592e5a8fa4f Lib/filecmp.py
--- a/Lib/filecmp.py	Tue Aug 14 21:45:25 2012 -0400
+++ b/Lib/filecmp.py	Thu Aug 23 10:17:37 2012 -0700
@@ -80,7 +80,7 @@
     dircmp(a, b, ignore=None, hide=None)
       A and B are directories.
       IGNORE is a list of names to ignore,
-        defaults to ['RCS', 'CVS', 'tags'].
+        defaults to ['RCS', 'CVS', 'tags', r'\.svn', r'\.hg', r'\.git', r'\.bzr', '_darcs'].
       HIDE is a list of names to hide,
         defaults to [os.curdir, os.pardir].
 
@@ -116,7 +116,7 @@
         else:
             self.hide = hide
         if ignore is None:
-            self.ignore = ['RCS', 'CVS', 'tags'] # Names ignored in comparison
+            self.ignore = ['RCS', 'CVS', 'tags', r'\.svn', r'\.hg', r'\.git', r'\.bzr', '_darcs'] # Names ignored in comparison
         else:
             self.ignore = ignore