diff --git a/Lib/test/mapping_tests.py b/Lib/test/mapping_tests.py
new file mode 100644
index 0000000..c0b70a7
--- /dev/null
+++ b/Lib/test/mapping_tests.py
@@ -0,0 +1,672 @@
+# tests common to dict and UserDict
+import unittest
+import UserDict
+
+
+class BasicTestMappingProtocol(unittest.TestCase):
+    # This base class can be used to check that an object conforms to the
+    # mapping protocol
+
+    # Functions that can be useful to override to adapt to dictionary
+    # semantics
+    _tested_class = None # which class is being tested (overwrite in subclasses)
+
+    def _reference(self):
+        """Return a dictionary of values which are invariant by storage
+        in the object under test."""
+        return {1:2, "key1":"value1", "key2":(1,2,3)}
+    def _empty_mapping(self):
+        """Return an empty mapping object"""
+        return self._tested_class()
+    def _full_mapping(self, data):
+        """Return a mapping object with the value contained in data
+        dictionary"""
+        x = self._empty_mapping()
+        for key, value in data.items():
+            x[key] = value
+        return x
+
+    def __init__(self, *args, **kw):
+        unittest.TestCase.__init__(self, *args, **kw)
+        self.reference = self._reference().copy()
+
+        # A (key, value) pair not in the mapping
+        key, value = self.reference.popitem()
+        self.other = {key:value}
+
+        # A (key, value) pair in the mapping
+        key, value = self.reference.popitem()
+        self.inmapping = {key:value}
+        self.reference[key] = value
+
+    def test_read(self):
+        # Test for read only operations on mapping
+        p = self._empty_mapping()
+        p1 = dict(p) #workaround for singleton objects
+        d = self._full_mapping(self.reference)
+        if d is p:
+            p = p1
+        #Indexing
+        for key, value in self.reference.items():
+            self.assertEqual(d[key], value)
+        knownkey = self.other.keys()[0]
+        self.failUnlessRaises(KeyError, lambda:d[knownkey])
+        #len
+        self.assertEqual(len(p), 0)
+        self.assertEqual(len(d), len(self.reference))
+        #has_key
+        for k in self.reference:
+            self.assert_(d.has_key(k))
+            self.assert_(k in d)
+        for k in self.other:
+            self.failIf(d.has_key(k))
+            self.failIf(k in d)
+        #cmp
+        self.assertEqual(cmp(p,p), 0)
+        self.assertEqual(cmp(d,d), 0)
+        self.assertEqual(cmp(p,d), -1)
+        self.assertEqual(cmp(d,p), 1)
+        #__non__zero__
+        if p: self.fail("Empty mapping must compare to False")
+        if not d: self.fail("Full mapping must compare to True")
+        # keys(), items(), iterkeys() ...
+        def check_iterandlist(iter, lst, ref):
+            self.assert_(hasattr(iter, 'next'))
+            self.assert_(hasattr(iter, '__iter__'))
+            x = list(iter)
+            self.assert_(set(x)==set(lst)==set(ref))
+        check_iterandlist(d.iterkeys(), d.keys(), self.reference.keys())
+        check_iterandlist(iter(d), d.keys(), self.reference.keys())
+        check_iterandlist(d.itervalues(), d.values(), self.reference.values())
+        check_iterandlist(d.iteritems(), d.items(), self.reference.items())
+        #get
+        key, value = d.iteritems().next()
+        knownkey, knownvalue = self.other.iteritems().next()
+        self.assertEqual(d.get(key, knownvalue), value)
+        self.assertEqual(d.get(knownkey, knownvalue), knownvalue)
+        self.failIf(knownkey in d)
+
+    def test_write(self):
+        # Test for write operations on mapping
+        p = self._empty_mapping()
+        #Indexing
+        for key, value in self.reference.items():
+            p[key] = value
+            self.assertEqual(p[key], value)
+        for key in self.reference.keys():
+            del p[key]
+            self.failUnlessRaises(KeyError, lambda:p[key])
+        p = self._empty_mapping()
+        #update
+        p.update(self.reference)
+        self.assertEqual(dict(p), self.reference)
+        items = p.items()
+        p = self._empty_mapping()
+        p.update(items)
+        self.assertEqual(dict(p), self.reference)
+        d = self._full_mapping(self.reference)
+        #setdefault
+        key, value = d.iteritems().next()
+        knownkey, knownvalue = self.other.iteritems().next()
+        self.assertEqual(d.setdefault(key, knownvalue), value)
+        self.assertEqual(d[key], value)
+        self.assertEqual(d.setdefault(knownkey, knownvalue), knownvalue)
+        self.assertEqual(d[knownkey], knownvalue)
+        #pop
+        self.assertEqual(d.pop(knownkey), knownvalue)
+        self.failIf(knownkey in d)
+        self.assertRaises(KeyError, d.pop, knownkey)
+        default = 909
+        d[knownkey] = knownvalue
+        self.assertEqual(d.pop(knownkey, default), knownvalue)
+        self.failIf(knownkey in d)
+        self.assertEqual(d.pop(knownkey, default), default)
+        #popitem
+        key, value = d.popitem()
+        self.failIf(key in d)
+        self.assertEqual(value, self.reference[key])
+        p=self._empty_mapping()
+        self.assertRaises(KeyError, p.popitem)
+
+    def test_constructor(self):
+        self.assertEqual(self._empty_mapping(), self._empty_mapping())
+
+    def test_bool(self):
+        self.assert_(not self._empty_mapping())
+        self.assert_(self.reference)
+        self.assert_(bool(self._empty_mapping()) is False)
+        self.assert_(bool(self.reference) is True)
+
+    def test_keys(self):
+        d = self._empty_mapping()
+        self.assertEqual(d.keys(), [])
+        d = self.reference
+        self.assert_(self.inmapping.keys()[0] in d.keys())
+        self.assert_(self.other.keys()[0] not in d.keys())
+        self.assertRaises(TypeError, d.keys, None)
+
+    def test_values(self):
+        d = self._empty_mapping()
+        self.assertEqual(d.values(), [])
+
+        self.assertRaises(TypeError, d.values, None)
+
+    def test_items(self):
+        d = self._empty_mapping()
+        self.assertEqual(d.items(), [])
+
+        self.assertRaises(TypeError, d.items, None)
+
+    def test_len(self):
+        d = self._empty_mapping()
+        self.assertEqual(len(d), 0)
+
+    def test_getitem(self):
+        d = self.reference
+        self.assertEqual(d[self.inmapping.keys()[0]], self.inmapping.values()[0])
+
+        self.assertRaises(TypeError, d.__getitem__)
+
+    def test_update(self):
+        # mapping argument
+        d = self._empty_mapping()
+        d.update(self.other)
+        self.assertEqual(d.items(), self.other.items())
+
+        # No argument
+        d = self._empty_mapping()
+        d.update()
+        self.assertEqual(d, self._empty_mapping())
+
+        # item sequence
+        d = self._empty_mapping()
+        d.update(self.other.items())
+        self.assertEqual(d.items(), self.other.items())
+
+        # Iterator
+        d = self._empty_mapping()
+        d.update(self.other.iteritems())
+        self.assertEqual(d.items(), self.other.items())
+
+        # FIXME: Doesn't work with UserDict
+        # self.assertRaises((TypeError, AttributeError), d.update, None)
+        self.assertRaises((TypeError, AttributeError), d.update, 42)
+
+        outerself = self
+        class SimpleUserDict:
+            def __init__(self):
+                self.d = outerself.reference
+            def keys(self):
+                return self.d.keys()
+            def __getitem__(self, i):
+                return self.d[i]
+        d.clear()
+        d.update(SimpleUserDict())
+        i1 = d.items()
+        i2 = self.reference.items()
+        i1.sort()
+        i2.sort()
+        self.assertEqual(i1, i2)
+
+        class Exc(Exception): pass
+
+        d = self._empty_mapping()
+        class FailingUserDict:
+            def keys(self):
+                raise Exc
+        self.assertRaises(Exc, d.update, FailingUserDict())
+
+        d.clear()
+
+        class FailingUserDict:
+            def keys(self):
+                class BogonIter:
+                    def __init__(self):
+                        self.i = 1
+                    def __iter__(self):
+                        return self
+                    def next(self):
+                        if self.i:
+                            self.i = 0
+                            return 'a'
+                        raise Exc
+                return BogonIter()
+            def __getitem__(self, key):
+                return key
+        self.assertRaises(Exc, d.update, FailingUserDict())
+
+        class FailingUserDict:
+            def keys(self):
+                class BogonIter:
+                    def __init__(self):
+                        self.i = ord('a')
+                    def __iter__(self):
+                        return self
+                    def next(self):
+                        if self.i <= ord('z'):
+                            rtn = chr(self.i)
+                            self.i += 1
+                            return rtn
+                        raise StopIteration
+                return BogonIter()
+            def __getitem__(self, key):
+                raise Exc
+        self.assertRaises(Exc, d.update, FailingUserDict())
+
+        d = self._empty_mapping()
+        class badseq(object):
+            def __iter__(self):
+                return self
+            def next(self):
+                raise Exc()
+
+        self.assertRaises(Exc, d.update, badseq())
+
+        self.assertRaises(ValueError, d.update, [(1, 2, 3)])
+
+    # no test_fromkeys or test_copy as both os.environ and selves don't support it
+
+    def test_get(self):
+        d = self._empty_mapping()
+        self.assert_(d.get(self.other.keys()[0]) is None)
+        self.assertEqual(d.get(self.other.keys()[0], 3), 3)
+        d = self.reference
+        self.assert_(d.get(self.other.keys()[0]) is None)
+        self.assertEqual(d.get(self.other.keys()[0], 3), 3)
+        self.assertEqual(d.get(self.inmapping.keys()[0]), self.inmapping.values()[0])
+        self.assertEqual(d.get(self.inmapping.keys()[0], 3), self.inmapping.values()[0])
+        self.assertRaises(TypeError, d.get)
+        self.assertRaises(TypeError, d.get, None, None, None)
+
+    def test_setdefault(self):
+        d = self._empty_mapping()
+        self.assertRaises(TypeError, d.setdefault)
+
+    def test_popitem(self):
+        d = self._empty_mapping()
+        self.assertRaises(KeyError, d.popitem)
+        self.assertRaises(TypeError, d.popitem, 42)
+
+    def test_pop(self):
+        d = self._empty_mapping()
+        k, v = self.inmapping.items()[0]
+        d[k] = v
+        self.assertRaises(KeyError, d.pop, self.other.keys()[0])
+
+        self.assertEqual(d.pop(k), v)
+        self.assertEqual(len(d), 0)
+
+        self.assertRaises(KeyError, d.pop, k)
+
+
+class TestMappingProtocol(BasicTestMappingProtocol):
+    def test_constructor(self):
+        BasicTestMappingProtocol.test_constructor(self)
+        self.assert_(self._empty_mapping() is not self._empty_mapping())
+        self.assertEqual(self._tested_class(x=1, y=2), {"x": 1, "y": 2})
+
+    def test_bool(self):
+        BasicTestMappingProtocol.test_bool(self)
+        self.assert_(not self._empty_mapping())
+        self.assert_(self._full_mapping({"x": "y"}))
+        self.assert_(bool(self._empty_mapping()) is False)
+        self.assert_(bool(self._full_mapping({"x": "y"})) is True)
+
+    def test_keys(self):
+        BasicTestMappingProtocol.test_keys(self)
+        d = self._empty_mapping()
+        self.assertEqual(d.keys(), [])
+        d = self._full_mapping({'a': 1, 'b': 2})
+        k = d.keys()
+        self.assert_('a' in k)
+        self.assert_('b' in k)
+        self.assert_('c' not in k)
+
+    def test_values(self):
+        BasicTestMappingProtocol.test_values(self)
+        d = self._full_mapping({1:2})
+        self.assertEqual(d.values(), [2])
+
+    def test_items(self):
+        BasicTestMappingProtocol.test_items(self)
+
+        d = self._full_mapping({1:2})
+        self.assertEqual(d.items(), [(1, 2)])
+
+    def test_has_key(self):
+        d = self._empty_mapping()
+        self.assert_(not d.has_key('a'))
+        d = self._full_mapping({'a': 1, 'b': 2})
+        k = d.keys()
+        k.sort()
+        self.assertEqual(k, ['a', 'b'])
+
+        self.assertRaises(TypeError, d.has_key)
+
+    def test_contains(self):
+        d = self._empty_mapping()
+        self.assert_(not ('a' in d))
+        self.assert_('a' not in d)
+        d = self._full_mapping({'a': 1, 'b': 2})
+        self.assert_('a' in d)
+        self.assert_('b' in d)
+        self.assert_('c' not in d)
+
+        self.assertRaises(TypeError, d.__contains__)
+
+    def test_len(self):
+        BasicTestMappingProtocol.test_len(self)
+        d = self._full_mapping({'a': 1, 'b': 2})
+        self.assertEqual(len(d), 2)
+
+    def test_getitem(self):
+        BasicTestMappingProtocol.test_getitem(self)
+        d = self._full_mapping({'a': 1, 'b': 2})
+        self.assertEqual(d['a'], 1)
+        self.assertEqual(d['b'], 2)
+        d['c'] = 3
+        d['a'] = 4
+        self.assertEqual(d['c'], 3)
+        self.assertEqual(d['a'], 4)
+        del d['b']
+        self.assertEqual(d, {'a': 4, 'c': 3})
+
+        self.assertRaises(TypeError, d.__getitem__)
+
+    def test_clear(self):
+        d = self._full_mapping({1:1, 2:2, 3:3})
+        d.clear()
+        self.assertEqual(d, {})
+
+        self.assertRaises(TypeError, d.clear, None)
+
+    def test_update(self):
+        BasicTestMappingProtocol.test_update(self)
+        # mapping argument
+        d = self._empty_mapping()
+        d.update({1:100})
+        d.update({2:20})
+        d.update({1:1, 2:2, 3:3})
+        self.assertEqual(d, {1:1, 2:2, 3:3})
+
+        # no argument
+        d.update()
+        self.assertEqual(d, {1:1, 2:2, 3:3})
+
+        # keyword arguments
+        d = self._empty_mapping()
+        d.update(x=100)
+        d.update(y=20)
+        d.update(x=1, y=2, z=3)
+        self.assertEqual(d, {"x":1, "y":2, "z":3})
+
+        # item sequence
+        d = self._empty_mapping()
+        d.update([("x", 100), ("y", 20)])
+        self.assertEqual(d, {"x":100, "y":20})
+
+        # Both item sequence and keyword arguments
+        d = self._empty_mapping()
+        d.update([("x", 100), ("y", 20)], x=1, y=2)
+        self.assertEqual(d, {"x":1, "y":2})
+
+        # iterator
+        d = self._full_mapping({1:3, 2:4})
+        d.update(self._full_mapping({1:2, 3:4, 5:6}).iteritems())
+        self.assertEqual(d, {1:2, 2:4, 3:4, 5:6})
+
+        class SimpleUserDict:
+            def __init__(self):
+                self.d = {1:1, 2:2, 3:3}
+            def keys(self):
+                return self.d.keys()
+            def __getitem__(self, i):
+                return self.d[i]
+        d.clear()
+        d.update(SimpleUserDict())
+        self.assertEqual(d, {1:1, 2:2, 3:3})
+
+    def test_fromkeys(self):
+        self.assertEqual(self._tested_class.fromkeys('abc'), {'a':None, 'b':None, 'c':None})
+        d = self._empty_mapping()
+        self.assert_(not(d.fromkeys('abc') is d))
+        self.assertEqual(d.fromkeys('abc'), {'a':None, 'b':None, 'c':None})
+        self.assertEqual(d.fromkeys((4,5),0), {4:0, 5:0})
+        self.assertEqual(d.fromkeys([]), {})
+        def g():
+            yield 1
+        self.assertEqual(d.fromkeys(g()), {1:None})
+        self.assertRaises(TypeError, {}.fromkeys, 3)
+        class dictlike(self._tested_class): pass
+        self.assertEqual(dictlike.fromkeys('a'), {'a':None})
+        self.assertEqual(dictlike().fromkeys('a'), {'a':None})
+        self.assert_(dictlike.fromkeys('a').__class__ is dictlike)
+        self.assert_(dictlike().fromkeys('a').__class__ is dictlike)
+        # FIXME: the following won't work with UserDict, because it's an old style class
+        # self.assert_(type(dictlike.fromkeys('a')) is dictlike)
+        class mydict(self._tested_class):
+            def __new__(cls):
+                return UserDict.UserDict()
+        ud = mydict.fromkeys('ab')
+        self.assertEqual(ud, {'a':None, 'b':None})
+        # FIXME: the following won't work with UserDict, because it's an old style class
+        # self.assert_(isinstance(ud, UserDict.UserDict))
+        self.assertRaises(TypeError, dict.fromkeys)
+
+        class Exc(Exception): pass
+
+        class baddict1(self._tested_class):
+            def __init__(self):
+                raise Exc()
+
+        self.assertRaises(Exc, baddict1.fromkeys, [1])
+
+        class BadSeq(object):
+            def __iter__(self):
+                return self
+            def next(self):
+                raise Exc()
+
+        self.assertRaises(Exc, self._tested_class.fromkeys, BadSeq())
+
+        class baddict2(self._tested_class):
+            def __setitem__(self, key, value):
+                raise Exc()
+
+        self.assertRaises(Exc, baddict2.fromkeys, [1])
+
+    def test_copy(self):
+        d = self._full_mapping({1:1, 2:2, 3:3})
+        self.assertEqual(d.copy(), {1:1, 2:2, 3:3})
+        d = self._empty_mapping()
+        self.assertEqual(d.copy(), d)
+        self.assert_(isinstance(d.copy(), d.__class__))
+        self.assertRaises(TypeError, d.copy, None)
+
+    def test_get(self):
+        BasicTestMappingProtocol.test_get(self)
+        d = self._empty_mapping()
+        self.assert_(d.get('c') is None)
+        self.assertEqual(d.get('c', 3), 3)
+        d = self._full_mapping({'a' : 1, 'b' : 2})
+        self.assert_(d.get('c') is None)
+        self.assertEqual(d.get('c', 3), 3)
+        self.assertEqual(d.get('a'), 1)
+        self.assertEqual(d.get('a', 3), 1)
+
+    def test_setdefault(self):
+        BasicTestMappingProtocol.test_setdefault(self)
+        d = self._empty_mapping()
+        self.assert_(d.setdefault('key0') is None)
+        d.setdefault('key0', [])
+        self.assert_(d.setdefault('key0') is None)
+        d.setdefault('key', []).append(3)
+        self.assertEqual(d['key'][0], 3)
+        d.setdefault('key', []).append(4)
+        self.assertEqual(len(d['key']), 2)
+
+    def test_popitem(self):
+        BasicTestMappingProtocol.test_popitem(self)
+        for copymode in -1, +1:
+            # -1: b has same structure as a
+            # +1: b is a.copy()
+            for log2size in range(12):
+                size = 2**log2size
+                a = self._empty_mapping()
+                b = self._empty_mapping()
+                for i in range(size):
+                    a[repr(i)] = i
+                    if copymode < 0:
+                        b[repr(i)] = i
+                if copymode > 0:
+                    b = a.copy()
+                for i in range(size):
+                    ka, va = ta = a.popitem()
+                    self.assertEqual(va, int(ka))
+                    kb, vb = tb = b.popitem()
+                    self.assertEqual(vb, int(kb))
+                    self.assert_(not(copymode < 0 and ta != tb))
+                self.assert_(not a)
+                self.assert_(not b)
+
+    def test_pop(self):
+        BasicTestMappingProtocol.test_pop(self)
+
+        # Tests for pop with specified key
+        d = self._empty_mapping()
+        k, v = 'abc', 'def'
+
+        # verify longs/ints get same value when key > 32 bits (for 64-bit archs)
+        # see SF bug #689659
+        x = 4503599627370496L
+        y = 4503599627370496
+        h = self._full_mapping({x: 'anything', y: 'something else'})
+        self.assertEqual(h[x], h[y])
+
+        self.assertEqual(d.pop(k, v), v)
+        d[k] = v
+        self.assertEqual(d.pop(k, 1), v)
+
+
+class TestHashMappingProtocol(TestMappingProtocol):
+
+    def test_getitem(self):
+        TestMappingProtocol.test_getitem(self)
+        class Exc(Exception): pass
+
+        class BadEq(object):
+            def __eq__(self, other):
+                raise Exc()
+
+        d = self._empty_mapping()
+        d[BadEq()] = 42
+        self.assertRaises(KeyError, d.__getitem__, 23)
+
+        class BadHash(object):
+            fail = False
+            def __hash__(self):
+                if self.fail:
+                    raise Exc()
+                else:
+                    return 42
+
+        d = self._empty_mapping()
+        x = BadHash()
+        d[x] = 42
+        x.fail = True
+        self.assertRaises(Exc, d.__getitem__, x)
+
+    def test_fromkeys(self):
+        TestMappingProtocol.test_fromkeys(self)
+        class mydict(self._tested_class):
+            def __new__(cls):
+                return UserDict.UserDict()
+        ud = mydict.fromkeys('ab')
+        self.assertEqual(ud, {'a':None, 'b':None})
+        self.assert_(isinstance(ud, UserDict.UserDict))
+
+    def test_pop(self):
+        TestMappingProtocol.test_pop(self)
+
+        class Exc(Exception): pass
+
+        class BadHash(object):
+            fail = False
+            def __hash__(self):
+                if self.fail:
+                    raise Exc()
+                else:
+                    return 42
+
+        d = self._empty_mapping()
+        x = BadHash()
+        d[x] = 42
+        x.fail = True
+        self.assertRaises(Exc, d.pop, x)
+
+    def test_mutatingiteration(self):
+        d = self._empty_mapping()
+        d[1] = 1
+        try:
+            for i in d:
+                d[i+1] = 1
+        except RuntimeError:
+            pass
+        else:
+            self.fail("changing dict size during iteration doesn't raise Error")
+
+    def test_repr(self):
+        d = self._empty_mapping()
+        self.assertEqual(repr(d), '{}')
+        d[1] = 2
+        self.assertEqual(repr(d), '{1: 2}')
+        d = self._empty_mapping()
+        d[1] = d
+        self.assertEqual(repr(d), '{1: {...}}')
+
+        class Exc(Exception): pass
+
+        class BadRepr(object):
+            def __repr__(self):
+                raise Exc()
+
+        d = self._full_mapping({1: BadRepr()})
+        self.assertRaises(Exc, repr, d)
+
+    def test_le(self):
+        self.assert_(not (self._empty_mapping() < self._empty_mapping()))
+        self.assert_(not (self._full_mapping({1: 2}) < self._full_mapping({1L: 2L})))
+
+        class Exc(Exception): pass
+
+        class BadCmp(object):
+            def __eq__(self, other):
+                raise Exc()
+
+        d1 = self._full_mapping({BadCmp(): 1})
+        d2 = self._full_mapping({1: 1})
+        try:
+            d1 < d2
+        except Exc:
+            pass
+        else:
+            self.fail("< didn't raise Exc")
+
+    def test_setdefault(self):
+        TestMappingProtocol.test_setdefault(self)
+
+        class Exc(Exception): pass
+
+        class BadHash(object):
+            fail = False
+            def __hash__(self):
+                if self.fail:
+                    raise Exc()
+                else:
+                    return 42
+
+        d = self._empty_mapping()
+        x = BadHash()
+        d[x] = 42
+        x.fail = True
+        self.assertRaises(Exc, d.setdefault, x, [])
diff --git a/Lib/test/output/test_types b/Lib/test/output/test_types
index b2f9429..b49ce0d 100644
--- a/Lib/test/output/test_types
+++ b/Lib/test/output/test_types
@@ -11,5 +11,5 @@
 6.5.1 Strings
 6.5.2 Tuples [see test_tuple.py]
 6.5.3 Lists [see test_list.py]
-6.6 Mappings == Dictionaries
+6.6 Mappings == Dictionaries [see test_dict.py]
 Buffers
diff --git a/Lib/test/test_os.py b/Lib/test/test_os.py
index db8d99e..1e283cd 100644
--- a/Lib/test/test_os.py
+++ b/Lib/test/test_os.py
@@ -205,9 +205,9 @@
         except TypeError:
             pass
 
-from test_userdict import TestMappingProtocol
+from test import mapping_tests
 
-class EnvironTests(TestMappingProtocol):
+class EnvironTests(mapping_tests.BasicTestMappingProtocol):
     """check that os.environ object conform to mapping protocol"""
     _tested_class = None
     def _reference(self):
diff --git a/Lib/test/test_shelve.py b/Lib/test/test_shelve.py
index f852be5..fda02da 100644
--- a/Lib/test/test_shelve.py
+++ b/Lib/test/test_shelve.py
@@ -74,14 +74,14 @@
         self.assertEqual(len(d2), 1)
 
 
-from test_userdict import TestMappingProtocol
+from test import mapping_tests
 
-class TestShelveBase(TestMappingProtocol):
+class TestShelveBase(mapping_tests.BasicTestMappingProtocol):
     fn = "shelftemp.db"
     counter = 0
     def __init__(self, *args, **kw):
         self._db = []
-        TestMappingProtocol.__init__(self, *args, **kw)
+        mapping_tests.BasicTestMappingProtocol.__init__(self, *args, **kw)
     _tested_class = shelve.Shelf
     def _reference(self):
         return {"key1":"value1", "key2":2, "key3":(1,2,3)}
diff --git a/Lib/test/test_types.py b/Lib/test/test_types.py
index 4b4e19c..31466b7 100644
--- a/Lib/test/test_types.py
+++ b/Lib/test/test_types.py
@@ -10,7 +10,6 @@
 if 0L: raise TestFailed, '0L is true instead of false'
 if 0.0: raise TestFailed, '0.0 is true instead of false'
 if '': raise TestFailed, '\'\' is true instead of false'
-if {}: raise TestFailed, '{} is true instead of false'
 if not 1: raise TestFailed, '1 is false instead of true'
 if not 1L: raise TestFailed, '1L is false instead of true'
 if not 1.0: raise TestFailed, '1.0 is false instead of true'
@@ -215,233 +214,8 @@
 
 print '6.5.3 Lists [see test_list.py]'
 
+print '6.6 Mappings == Dictionaries [see test_dict.py]'
 
-print '6.6 Mappings == Dictionaries'
-# calling built-in types without argument must return empty
-if dict() != {}: raise TestFailed,'dict() does not return {}'
-d = {}
-if d.keys() != []: raise TestFailed, '{}.keys()'
-if d.values() != []: raise TestFailed, '{}.values()'
-if d.items() != []: raise TestFailed, '{}.items()'
-if d.has_key('a') != 0: raise TestFailed, '{}.has_key(\'a\')'
-if ('a' in d) != 0: raise TestFailed, "'a' in {}"
-if ('a' not in d) != 1: raise TestFailed, "'a' not in {}"
-if len(d) != 0: raise TestFailed, 'len({})'
-d = {'a': 1, 'b': 2}
-if len(d) != 2: raise TestFailed, 'len(dict)'
-k = d.keys()
-k.sort()
-if k != ['a', 'b']: raise TestFailed, 'dict keys()'
-if d.has_key('a') and d.has_key('b') and not d.has_key('c'): pass
-else: raise TestFailed, 'dict keys()'
-if 'a' in d and 'b' in d and 'c' not in d: pass
-else: raise TestFailed, 'dict keys() # in/not in version'
-if d['a'] != 1 or d['b'] != 2: raise TestFailed, 'dict item'
-d['c'] = 3
-d['a'] = 4
-if d['c'] != 3 or d['a'] != 4: raise TestFailed, 'dict item assignment'
-del d['b']
-if d != {'a': 4, 'c': 3}: raise TestFailed, 'dict item deletion'
-# dict.clear()
-d = {1:1, 2:2, 3:3}
-d.clear()
-if d != {}: raise TestFailed, 'dict clear'
-# dict.update()
-d.update({1:100})
-d.update({2:20})
-d.update({1:1, 2:2, 3:3})
-if d != {1:1, 2:2, 3:3}: raise TestFailed, 'dict update'
-d.clear()
-try: d.update(None)
-except (TypeError, AttributeError): pass
-else: raise TestFailed, 'dict.update(None), AttributeError expected'
-class SimpleUserDict:
-    def __init__(self):
-        self.d = {1:1, 2:2, 3:3}
-    def keys(self):
-        return self.d.keys()
-    def __getitem__(self, i):
-        return self.d[i]
-d.update(SimpleUserDict())
-if d != {1:1, 2:2, 3:3}: raise TestFailed, 'dict.update(instance)'
-d.clear()
-class FailingUserDict:
-    def keys(self):
-        raise ValueError
-try: d.update(FailingUserDict())
-except ValueError: pass
-else: raise TestFailed, 'dict.keys() expected ValueError'
-class FailingUserDict:
-    def keys(self):
-        class BogonIter:
-            def __iter__(self):
-                raise ValueError
-        return BogonIter()
-try: d.update(FailingUserDict())
-except ValueError: pass
-else: raise TestFailed, 'iter(dict.keys()) expected ValueError'
-class FailingUserDict:
-    def keys(self):
-        class BogonIter:
-            def __init__(self):
-                self.i = 1
-            def __iter__(self):
-                return self
-            def next(self):
-                if self.i:
-                    self.i = 0
-                    return 'a'
-                raise ValueError
-        return BogonIter()
-    def __getitem__(self, key):
-        return key
-try: d.update(FailingUserDict())
-except ValueError: pass
-else: raise TestFailed, 'iter(dict.keys()).next() expected ValueError'
-class FailingUserDict:
-    def keys(self):
-        class BogonIter:
-            def __init__(self):
-                self.i = ord('a')
-            def __iter__(self):
-                return self
-            def next(self):
-                if self.i <= ord('z'):
-                    rtn = chr(self.i)
-                    self.i += 1
-                    return rtn
-                raise StopIteration
-        return BogonIter()
-    def __getitem__(self, key):
-        raise ValueError
-try: d.update(FailingUserDict())
-except ValueError: pass
-else: raise TestFailed, 'dict.update(), __getitem__ expected ValueError'
-# dict.fromkeys()
-if dict.fromkeys('abc') != {'a':None, 'b':None, 'c':None}:
-    raise TestFailed, 'dict.fromkeys did not work as a class method'
-d = {}
-if d.fromkeys('abc') is d:
-    raise TestFailed, 'dict.fromkeys did not return a new dict'
-if d.fromkeys('abc') != {'a':None, 'b':None, 'c':None}:
-    raise TestFailed, 'dict.fromkeys failed with default value'
-if d.fromkeys((4,5),0) != {4:0, 5:0}:
-    raise TestFailed, 'dict.fromkeys failed with specified value'
-if d.fromkeys([]) != {}:
-    raise TestFailed, 'dict.fromkeys failed with null sequence'
-def g():
-    yield 1
-if d.fromkeys(g()) != {1:None}:
-    raise TestFailed, 'dict.fromkeys failed with a generator'
-try: {}.fromkeys(3)
-except TypeError: pass
-else: raise TestFailed, 'dict.fromkeys failed to raise TypeError'
-class dictlike(dict): pass
-if dictlike.fromkeys('a') != {'a':None}:
-    raise TestFailed, 'dictsubclass.fromkeys did not inherit'
-if dictlike().fromkeys('a') != {'a':None}:
-    raise TestFailed, 'dictsubclass.fromkeys did not inherit'
-if type(dictlike.fromkeys('a')) is not dictlike:
-    raise TestFailed, 'dictsubclass.fromkeys created wrong type'
-if type(dictlike().fromkeys('a')) is not dictlike:
-    raise TestFailed, 'dictsubclass.fromkeys created wrong type'
-from UserDict import UserDict
-class mydict(dict):
-    def __new__(cls):
-        return UserDict()
-ud = mydict.fromkeys('ab')
-if ud != {'a':None, 'b':None} or not isinstance(ud,UserDict):
-    raise TestFailed, 'fromkeys did not instantiate using  __new__'
-# dict.copy()
-d = {1:1, 2:2, 3:3}
-if d.copy() != {1:1, 2:2, 3:3}: raise TestFailed, 'dict copy'
-if {}.copy() != {}: raise TestFailed, 'empty dict copy'
-# dict.get()
-d = {}
-if d.get('c') is not None: raise TestFailed, 'missing {} get, no 2nd arg'
-if d.get('c', 3) != 3: raise TestFailed, 'missing {} get, w/ 2nd arg'
-d = {'a' : 1, 'b' : 2}
-if d.get('c') is not None: raise TestFailed, 'missing dict get, no 2nd arg'
-if d.get('c', 3) != 3: raise TestFailed, 'missing dict get, w/ 2nd arg'
-if d.get('a') != 1: raise TestFailed, 'present dict get, no 2nd arg'
-if d.get('a', 3) != 1: raise TestFailed, 'present dict get, w/ 2nd arg'
-# dict.setdefault()
-d = {}
-if d.setdefault('key0') is not None:
-    raise TestFailed, 'missing {} setdefault, no 2nd arg'
-if d.setdefault('key0') is not None:
-    raise TestFailed, 'present {} setdefault, no 2nd arg'
-d.setdefault('key', []).append(3)
-if d['key'][0] != 3:
-    raise TestFailed, 'missing {} setdefault, w/ 2nd arg'
-d.setdefault('key', []).append(4)
-if len(d['key']) != 2:
-    raise TestFailed, 'present {} setdefault, w/ 2nd arg'
-# dict.popitem()
-for copymode in -1, +1:
-    # -1: b has same structure as a
-    # +1: b is a.copy()
-    for log2size in range(12):
-        size = 2**log2size
-        a = {}
-        b = {}
-        for i in range(size):
-            a[repr(i)] = i
-            if copymode < 0:
-                b[repr(i)] = i
-        if copymode > 0:
-            b = a.copy()
-        for i in range(size):
-            ka, va = ta = a.popitem()
-            if va != int(ka): raise TestFailed, "a.popitem: %s" % str(ta)
-            kb, vb = tb = b.popitem()
-            if vb != int(kb): raise TestFailed, "b.popitem: %s" % str(tb)
-            if copymode < 0 and ta != tb:
-                raise TestFailed, "a.popitem != b.popitem: %s, %s" % (
-                    str(ta), str(tb))
-        if a: raise TestFailed, 'a not empty after popitems: %s' % str(a)
-        if b: raise TestFailed, 'b not empty after popitems: %s' % str(b)
-
-d.clear()
-try: d.popitem()
-except KeyError: pass
-else: raise TestFailed, "{}.popitem doesn't raise KeyError"
-
-# Tests for pop with specified key
-d.clear()
-k, v = 'abc', 'def'
-d[k] = v
-try: d.pop('ghi')
-except KeyError: pass
-else: raise TestFailed, "{}.pop(k) doesn't raise KeyError when k not in dictionary"
-
-if d.pop(k) != v: raise TestFailed, "{}.pop(k) doesn't find known key/value pair"
-if len(d) > 0: raise TestFailed, "{}.pop(k) failed to remove the specified pair"
-
-try: d.pop(k)
-except KeyError: pass
-else: raise TestFailed, "{}.pop(k) doesn't raise KeyError when dictionary is empty"
-
-# verify longs/ints get same value when key > 32 bits (for 64-bit archs)
-# see SF bug #689659
-x = 4503599627370496L
-y = 4503599627370496
-h = {x: 'anything', y: 'something else'}
-if h[x] != h[y]:
-    raise TestFailed, "long/int key should match"
-
-if d.pop(k, v) != v: raise TestFailed, "{}.pop(k, v) doesn't return default value"
-d[k] = v
-if d.pop(k, 1) != v: raise TestFailed, "{}.pop(k, v) doesn't find known key/value pair"
-
-d[1] = 1
-try:
-    for i in d:
-        d[i+1] = 1
-except RuntimeError:
-    pass
-else:
-    raise TestFailed, "changing dict size during iteration doesn't raise Error"
 
 try: type(1, 2)
 except TypeError: pass
diff --git a/Lib/test/test_userdict.py b/Lib/test/test_userdict.py
index 0ed4369..f67e55b 100644
--- a/Lib/test/test_userdict.py
+++ b/Lib/test/test_userdict.py
@@ -1,126 +1,9 @@
 # Check every path through every method of UserDict
 
-import test.test_support, unittest
+import unittest
+from test import test_support, mapping_tests
 import UserDict
 
-class TestMappingProtocol(unittest.TestCase):
-    # This base class can be used to check that an object conforms to the
-    # mapping protocol
-
-    # Functions that can be useful to override to adapt to dictionary
-    # semantics
-    _tested_class = dict   # which class is being tested
-
-    def _reference(self):
-        """Return a dictionary of values which are invariant by storage
-        in the object under test."""
-        return {1:2, "key1":"value1", "key2":(1,2,3)}
-    def _empty_mapping(self):
-        """Return an empty mapping object"""
-        return self._tested_class()
-    def _full_mapping(self, data):
-        """Return a mapping object with the value contained in data
-        dictionary"""
-        x = self._empty_mapping()
-        for key, value in data.items():
-            x[key] = value
-        return x
-
-    def __init__(self, *args, **kw):
-        unittest.TestCase.__init__(self, *args, **kw)
-        self.reference = self._reference().copy()
-        key, value = self.reference.popitem()
-        self.other = {key:value}
-
-    def test_read(self):
-        # Test for read only operations on mapping
-        p = self._empty_mapping()
-        p1 = dict(p) #workaround for singleton objects
-        d = self._full_mapping(self.reference)
-        if d is p:
-            p = p1
-        #Indexing
-        for key, value in self.reference.items():
-            self.assertEqual(d[key], value)
-        knownkey = self.other.keys()[0]
-        self.failUnlessRaises(KeyError, lambda:d[knownkey])
-        #len
-        self.assertEqual(len(p), 0)
-        self.assertEqual(len(d), len(self.reference))
-        #has_key
-        for k in self.reference:
-            self.assert_(d.has_key(k))
-            self.assert_(k in d)
-        for k in self.other:
-            self.failIf(d.has_key(k))
-            self.failIf(k in d)
-        #cmp
-        self.assertEqual(cmp(p,p), 0)
-        self.assertEqual(cmp(d,d), 0)
-        self.assertEqual(cmp(p,d), -1)
-        self.assertEqual(cmp(d,p), 1)
-        #__non__zero__
-        if p: self.fail("Empty mapping must compare to False")
-        if not d: self.fail("Full mapping must compare to True")
-        # keys(), items(), iterkeys() ...
-        def check_iterandlist(iter, lst, ref):
-            self.assert_(hasattr(iter, 'next'))
-            self.assert_(hasattr(iter, '__iter__'))
-            x = list(iter)
-            self.assert_(set(x)==set(lst)==set(ref))
-        check_iterandlist(d.iterkeys(), d.keys(), self.reference.keys())
-        check_iterandlist(iter(d), d.keys(), self.reference.keys())
-        check_iterandlist(d.itervalues(), d.values(), self.reference.values())
-        check_iterandlist(d.iteritems(), d.items(), self.reference.items())
-        #get
-        key, value = d.iteritems().next()
-        knownkey, knownvalue = self.other.iteritems().next()
-        self.assertEqual(d.get(key, knownvalue), value)
-        self.assertEqual(d.get(knownkey, knownvalue), knownvalue)
-        self.failIf(knownkey in d)
-
-    def test_write(self):
-        # Test for write operations on mapping
-        p = self._empty_mapping()
-        #Indexing
-        for key, value in self.reference.items():
-            p[key] = value
-            self.assertEqual(p[key], value)
-        for key in self.reference.keys():
-            del p[key]
-            self.failUnlessRaises(KeyError, lambda:p[key])
-        p = self._empty_mapping()
-        #update
-        p.update(self.reference)
-        self.assertEqual(dict(p), self.reference)
-        items = p.items()
-        p = self._empty_mapping()
-        p.update(items)
-        self.assertEqual(dict(p), self.reference)
-        d = self._full_mapping(self.reference)
-        #setdefault
-        key, value = d.iteritems().next()
-        knownkey, knownvalue = self.other.iteritems().next()
-        self.assertEqual(d.setdefault(key, knownvalue), value)
-        self.assertEqual(d[key], value)
-        self.assertEqual(d.setdefault(knownkey, knownvalue), knownvalue)
-        self.assertEqual(d[knownkey], knownvalue)
-        #pop
-        self.assertEqual(d.pop(knownkey), knownvalue)
-        self.failIf(knownkey in d)
-        self.assertRaises(KeyError, d.pop, knownkey)
-        default = 909
-        d[knownkey] = knownvalue
-        self.assertEqual(d.pop(knownkey, default), knownvalue)
-        self.failIf(knownkey in d)
-        self.assertEqual(d.pop(knownkey, default), default)
-        #popitem
-        key, value = d.popitem()
-        self.failIf(key in d)
-        self.assertEqual(value, self.reference[key])
-        p=self._empty_mapping()
-        self.assertRaises(KeyError, p.popitem)
-
 d0 = {}
 d1 = {"one": 1}
 d2 = {"one": 1, "two": 2}
@@ -128,7 +11,7 @@
 d4 = {"one": None, "two": None}
 d5 = {"one": 1, "two": 1}
 
-class UserDictTest(TestMappingProtocol):
+class UserDictTest(mapping_tests.TestHashMappingProtocol):
     _tested_class = UserDict.IterableUserDict
 
     def test_all(self):
@@ -273,9 +156,14 @@
 
     Used to test and demonstrate DictMixin
     """
-    def __init__(self):
+    def __init__(self, other=None, **kwargs):
         self.keylist = []
         self.valuelist = []
+        if other is not None:
+            for (key, value) in other:
+                self[key] = value
+        for (key, value) in kwargs.iteritems():
+            self[key] = value
     def __getitem__(self, key):
         try:
             i = self.keylist.index(key)
@@ -298,8 +186,19 @@
         self.valuelist.pop(i)
     def keys(self):
         return list(self.keylist)
+    def copy(self):
+        d = self.__class__()
+        for key, value in self.iteritems():
+            d[key] = value
+        return d
+    def fromkeys(cls, keys, value=None):
+        d = cls()
+        for key in keys:
+            d[key] = value
+        return d
+    fromkeys = classmethod(fromkeys)
 
-class UserDictMixinTest(TestMappingProtocol):
+class UserDictMixinTest(mapping_tests.TestMappingProtocol):
     _tested_class = SeqDict
 
     def test_all(self):
@@ -393,8 +292,7 @@
         self.assertEqual(s, t)
 
 def test_main():
-    test.test_support.run_unittest(
-        TestMappingProtocol,
+    test_support.run_unittest(
         UserDictTest,
         UserDictMixinTest
     )
diff --git a/Lib/test/test_weakref.py b/Lib/test/test_weakref.py
index 2924313..cf5d0a4 100644
--- a/Lib/test/test_weakref.py
+++ b/Lib/test/test_weakref.py
@@ -912,16 +912,16 @@
         self.assertEqual(len(d), 0)
         self.assertEqual(count, 2)
 
-from test_userdict import TestMappingProtocol
+from test import mapping_tests
 
-class WeakValueDictionaryTestCase(TestMappingProtocol):
+class WeakValueDictionaryTestCase(mapping_tests.BasicTestMappingProtocol):
     """Check that WeakValueDictionary conforms to the mapping protocol"""
     __ref = {"key1":Object(1), "key2":Object(2), "key3":Object(3)}
     _tested_class = weakref.WeakValueDictionary
     def _reference(self):
         return self.__ref.copy()
 
-class WeakKeyDictionaryTestCase(TestMappingProtocol):
+class WeakKeyDictionaryTestCase(mapping_tests.BasicTestMappingProtocol):
     """Check that WeakKeyDictionary conforms to the mapping protocol"""
     __ref = {Object("key1"):1, Object("key2"):2, Object("key3"):3}
     _tested_class = weakref.WeakKeyDictionary