[Python-checkins] python/dist/src/Lib/test test_builtin.py, 1.33, 1.34

[jhylton at users.sourceforge.net]

Update of /cvsroot/python/python/dist/src/Lib/test
In directory sc8-pr-cvs1.sourceforge.net:/tmp/cvs-serv9225/Lib/test

Modified Files:
	test_builtin.py 
Log Message:
Subclasses of string can no longer be interned.  The semantics of
interning were not clear here -- a subclass could be mutable, for
example -- and had bugs.  Explicitly interning a subclass of string
via intern() will raise a TypeError.  Internal operations that attempt
to intern a string subclass will have no effect.

Added a few tests to test_builtin that includes the old buggy code and
verifies that calls like PyObject_SetAttr() don't fail.  Perhaps these
tests should have gone in test_string.


Index: test_builtin.py
===================================================================
RCS file: /cvsroot/python/python/dist/src/Lib/test/test_builtin.py,v
retrieving revision 1.33
retrieving revision 1.34
diff -C2 -d -r1.33 -r1.34
*** test_builtin.py	7 Aug 2004 04:55:30 -0000	1.33
--- test_builtin.py	7 Aug 2004 19:20:05 -0000	1.34
***************
*** 609,612 ****
--- 609,629 ----
          self.assert_(intern(s2) is s)
  
+         # Subclasses of string can't be interned, because they
+         # provide too much opportunity for insane things to happen.
+         # We don't want them in the interned dict and if they aren't
+         # actually interned, we don't want to create the appearance
+         # that they are by allowing intern() to succeeed.
+         class S(str):
+             def __hash__(self):
+                 return 123
+ 
+         self.assertRaises(TypeError, intern, S("abc"))
+ 
+         # It's still safe to pass these strings to routines that
+         # call intern internally, e.g. PyObject_SetAttr().
+         s = S("abc")
+         setattr(s, s, s)
+         self.assertEqual(getattr(s, s), s)
+ 
      def test_iter(self):
          self.assertRaises(TypeError, iter)