=== modified file 'Lib/test/test_set.py'
--- Lib/test/test_set.py	2008-03-25 06:35:10 +0000
+++ Lib/test/test_set.py	2008-05-07 20:53:03 +0000
@@ -63,7 +63,7 @@
             self.assertEqual(c in self.s, c in self.d)
         self.assertRaises(TypeError, self.s.__contains__, [[]])
         s = self.thetype([frozenset(self.letters)])
-        self.assert_(self.thetype(self.letters) in s)
+        self.assert_(frozenset(self.letters) in s)
 
     def test_union(self):
         u = self.s.union(self.otherword)
@@ -356,10 +356,10 @@
         self.assertRaises(KeyError, self.s.remove, 'Q')
         self.assertRaises(TypeError, self.s.remove, [])
         s = self.thetype([frozenset(self.word)])
-        self.assert_(self.thetype(self.word) in s)
-        s.remove(self.thetype(self.word))
-        self.assert_(self.thetype(self.word) not in s)
-        self.assertRaises(KeyError, self.s.remove, self.thetype(self.word))
+        self.assert_(frozenset(self.word) in s)
+        s.remove(frozenset(self.word))
+        self.assert_(frozenset(self.word) not in s)
+        self.assertRaises(KeyError, self.s.remove, frozenset(self.word))
 
     def test_remove_keyerror_unpacking(self):
         # bug:  www.python.org/sf/1576657
@@ -378,10 +378,10 @@
         self.s.discard('Q')
         self.assertRaises(TypeError, self.s.discard, [])
         s = self.thetype([frozenset(self.word)])
-        self.assert_(self.thetype(self.word) in s)
-        s.discard(self.thetype(self.word))
-        self.assert_(self.thetype(self.word) not in s)
-        s.discard(self.thetype(self.word))
+        self.assert_(frozenset(self.word) in s)
+        s.discard(frozenset(self.word))
+        self.assert_(frozenset(self.word) not in s)
+        s.discard(frozenset(self.word))
 
     def test_pop(self):
         for i in xrange(len(self.s)):
@@ -528,6 +528,13 @@
         s.__init__(self.otherword)
         self.assertEqual(s, set(self.word))
 
+    def test_contains_as_key(self):
+        for c in self.letters:
+            self.assertEqual(c in self.s, c in self.d)
+        self.assertRaises(TypeError, self.s.__contains__, [[]])
+        s = self.thetype([frozenset(self.letters)])
+        self.assert_(self.thetype(self.letters) in s)
+
     def test_singleton_empty_frozenset(self):
         f = frozenset()
         efs = [frozenset(), frozenset([]), frozenset(()), frozenset(''),

=== modified file 'Objects/setobject.c'
--- Objects/setobject.c	2008-02-12 19:05:36 +0000
+++ Objects/setobject.c	2008-05-08 02:40:19 +0000
@@ -1080,10 +1080,8 @@
      t=set(a); a.clear(); a.update(b); b.clear(); b.update(t); del t
 
    The function always succeeds and it leaves both objects in a stable state.
-   Useful for creating temporary frozensets from sets for membership testing 
-   in __contains__(), discard(), and remove().  Also useful for operations
-   that update in-place (by allowing an intermediate result to be swapped 
-   into one of the original inputs).
+   Useful for operations that update in-place (by allowing an intermediate
+   result to be swapped into one of the original inputs).
 */
 
 static void
@@ -1093,7 +1091,6 @@
 	setentry *u;
 	setentry *(*f)(PySetObject *so, PyObject *key, long hash);
 	setentry tab[PySet_MINSIZE];
-	long h;
 
 	t = a->fill;     a->fill   = b->fill;        b->fill  = t;
 	t = a->used;     a->used   = b->used;        b->used  = t;
@@ -1115,13 +1112,8 @@
 		memcpy(b->smalltable, tab, sizeof(tab));
 	}
 
-	if (PyType_IsSubtype(Py_TYPE(a), &PyFrozenSet_Type)  &&
-	    PyType_IsSubtype(Py_TYPE(b), &PyFrozenSet_Type)) {
-		h = a->hash;     a->hash = b->hash;  b->hash = h;
-	} else {
-		a->hash = -1;
-		b->hash = -1;
-	}
+	assert(!PyFrozenSet_Check(a) && !PyFrozenSet_Check(b));
+	assert(a->hash == -1 && b->hash == -1);
 }
 
 static PyObject *
@@ -1750,23 +1742,7 @@
 static int
 set_contains(PySetObject *so, PyObject *key)
 {
-	PyObject *tmpkey;
-	int rv;
-
-	rv = set_contains_key(so, key);
-	if (rv == -1) {
-		if (!PyAnySet_Check(key) || !PyErr_ExceptionMatches(PyExc_TypeError))
-			return -1;
-		PyErr_Clear();
-		tmpkey = make_new_set(&PyFrozenSet_Type, NULL);
-		if (tmpkey == NULL)
-			return -1;
-		set_swap_bodies((PySetObject *)tmpkey, (PySetObject *)key);
-		rv = set_contains(so, tmpkey);
-		set_swap_bodies((PySetObject *)tmpkey, (PySetObject *)key);
-		Py_DECREF(tmpkey);
-	}
-	return rv;
+	return set_contains_key(so, key);
 }
 
 static PyObject *
@@ -1785,23 +1761,12 @@
 static PyObject *
 set_remove(PySetObject *so, PyObject *key)
 {
-	PyObject *tmpkey, *result;
 	int rv;
 
 	rv = set_discard_key(so, key);
-	if (rv == -1) {
-		if (!PyAnySet_Check(key) || !PyErr_ExceptionMatches(PyExc_TypeError))
-			return NULL;
-		PyErr_Clear();
-		tmpkey = make_new_set(&PyFrozenSet_Type, NULL);
-		if (tmpkey == NULL)
-			return NULL;
-		set_swap_bodies((PySetObject *)tmpkey, (PySetObject *)key);
-		result = set_remove(so, tmpkey);
-		set_swap_bodies((PySetObject *)tmpkey, (PySetObject *)key);
-		Py_DECREF(tmpkey);
-		return result;
-	} else if (rv == DISCARD_NOTFOUND) {
+	if (rv == -1)
+		return NULL;
+	else if (rv == DISCARD_NOTFOUND) {
 		set_key_error(key);
 		return NULL;
 	}
@@ -1816,23 +1781,11 @@
 static PyObject *
 set_discard(PySetObject *so, PyObject *key)
 {
-	PyObject *tmpkey, *result;
 	int rv;
 
 	rv = set_discard_key(so, key);
-	if (rv == -1) {
-		if (!PyAnySet_Check(key) || !PyErr_ExceptionMatches(PyExc_TypeError))
-			return NULL;
-		PyErr_Clear();
-		tmpkey = make_new_set(&PyFrozenSet_Type, NULL);
-		if (tmpkey == NULL)
-			return NULL;
-		set_swap_bodies((PySetObject *)tmpkey, (PySetObject *)key);
-		result = set_discard(so, tmpkey);
-		set_swap_bodies((PySetObject *)tmpkey, (PySetObject *)key);
-		Py_DECREF(tmpkey);
-		return result;
-	}
+	if (rv == -1)
+		return NULL;
 	Py_RETURN_NONE;
 }