Raise an error when an invalid argument is passed to persistent.simple_new.

src/persistent/cPersistence.c

@@ -1235,6 +1235,12 @@ Per_setstate(cPersistentObject *self)
 static PyObject *
 simple_new(PyObject *self, PyObject *type_object)
 {
+  if (!PyType_Check(type_object))
+    {
+      PyErr_SetString(PyExc_TypeError,
+                      "simple_new argument must be a type object.");
+      return NULL;
+    }
   return PyType_GenericNew((PyTypeObject *)type_object, NULL, NULL);
 }
 

src/persistent/tests/persistent.txt

@@ -462,7 +462,7 @@ that might be tedious.
 Interfaces
 ----------
 
-Some versions of Zope and ZODB have the `zope.interfaces` package available.
+Some versions of Zope and ZODB have the `zope.interface` package available.
 If it is available, then persistent will be associated with several
 interfaces.  It's hard to write a doctest test that runs the tests only if
 `zope.interface` is available, so this test looks a little unusual.  One

src/persistent/tests/test_persistent.py

@@ -13,7 +13,7 @@
 ##############################################################################
 import unittest
 from zope.testing import doctest
-from persistent import Persistent
+from persistent import Persistent, simple_new
 
 class P(Persistent):
     def __init__(self):
@@ -35,6 +35,13 @@ def cpersistent_setstate_pointer_sanity():
     TypeError: this object has no instance dictionary
     """
 
+def cpersistent_simple_new_invalid_argument():
+    """
+    >>> simple_new('')
+    Traceback (most recent call last):
+    ...
+    TypeError: simple_new argument must be a type object.
+    """
 
 def test_suite():
     return unittest.TestSuite((