Index: Objects/exceptions.c
===================================================================
--- Objects/exceptions.c	(Revision 56829)
+++ Objects/exceptions.c	(Arbeitskopie)
@@ -38,18 +38,31 @@
     /* the dict is created on the fly in PyObject_GenericSetAttr */
     self->message = self->dict = NULL;
 
-    self->args = PyTuple_New(0);
-    if (!self->args) {
+    if (!args) {
+        /* MemoryError instantiation */
+        args = PyTuple_New(0);
+        if (!args) {
+            Py_DECREF(self);
+            return NULL;
+        }
+    } else {
+        Py_INCREF(args);
+    }
+    
+    self->args = args;
+
+    /* Since the args can be overwritten in __init__, we have to store
+       the original args somewhere for pickling. */
+    if (PyObject_SetAttrString((PyObject *)self, "__newargs__", args) < 0) {
         Py_DECREF(self);
         return NULL;
     }
-
+   
     self->message = PyString_FromString("");
     if (!self->message) {
         Py_DECREF(self);
         return NULL;
     }
-
     return (PyObject *)self;
 }
 
@@ -147,10 +160,23 @@
 static PyObject *
 BaseException_reduce(PyBaseExceptionObject *self)
 {
+    PyObject *result;
+    PyObject *newargs = PyObject_GetAttrString((PyObject *)self, "__newargs__");
+    if (!newargs) {
+        if (PyErr_ExceptionMatches(PyExc_AttributeError)) {
+            PyErr_SetString(PyExc_AttributeError,
+                            "To pickle exceptions via BaseException.__reduce__, "
+                            "you need to set the __newargs__ attribute in your "
+                            "custom __new__ method.");
+        }
+        return NULL;
+    }
     if (self->args && self->dict)
-        return PyTuple_Pack(3, Py_Type(self), self->args, self->dict);
+        result = PyTuple_Pack(3, Py_Type(self), newargs, self->dict);
     else
-        return PyTuple_Pack(2, Py_Type(self), self->args);
+        result = PyTuple_Pack(2, Py_Type(self), newargs);
+    Py_DECREF(newargs);
+    return result;
 }
 
 /*
Index: Lib/test/test_exceptions.py
===================================================================
--- Lib/test/test_exceptions.py	(Revision 56829)
+++ Lib/test/test_exceptions.py	(Arbeitskopie)
@@ -9,6 +9,16 @@
                                 guard_warnings_filter)
 from test.test_pep352 import ignore_message_warning
 
+class NaiveException(Exception):
+    def __init__(self, x):
+        self.x = x
+
+class SomewhatNaiveException(Exception):
+    def __init__(self, x):
+        self.x = x
+        Exception.__init__(self)
+
+
 # XXX This is not really enough, each *operation* should be tested!
 
 class ExceptionTests(unittest.TestCase):
@@ -263,6 +273,10 @@
                 {'message' : '', 'args' : (u'\u3042', 0, 1, 'ouch'),
                  'object' : u'\u3042', 'reason' : 'ouch',
                  'start' : 0, 'end' : 1}),
+            (NaiveException, ('foo',),
+                {'message': '', 'args': ('foo',), 'x': 'foo'}),
+            (SomewhatNaiveException, ('foo',),
+                {'message': '', 'args': (), 'x': 'foo'}),
         ]
         try:
             exceptionList.append(
@@ -283,7 +297,8 @@
                     if type(e) is not exc:
                         raise
                     # Verify module name
-                    self.assertEquals(type(e).__module__, 'exceptions')
+                    if not type(e).__name__.endswith('NaiveException'):
+                        self.assertEquals(type(e).__module__, 'exceptions')
                     # Verify no ref leaks in Exc_str()
                     s = str(e)
                     for checkArgName in expected: