Index: Lib/pdb.py
===================================================================
--- Lib/pdb.py	(revision 85046)
+++ Lib/pdb.py	(working copy)
@@ -1275,7 +1275,7 @@
         (Pdb) global list_options; list_options = ['-l']
         (Pdb)
         """
-        self.message(self.help_exec.__doc__.strip())
+        self.message((self.help_exec.__doc__ or '').strip())
 
     def help_pdb(self):
         help()
@@ -1343,10 +1343,13 @@
     'debug', 'quit',
 ]
 
+if __doc__ is None:
+    __doc__ = ''
+
 docs = set()
 for _command in _help_order:
-    __doc__ += getattr(Pdb, 'do_' + _command).__doc__.strip() + '\n\n'
-__doc__ += Pdb.help_exec.__doc__
+    __doc__ += (getattr(Pdb, 'do_' + _command).__doc__ or '').strip() + '\n\n'
+__doc__ += (Pdb.help_exec.__doc__ or '')
 
 del _help_order, _command