Index: Lib/test/test_functools.py
===================================================================
--- Lib/test/test_functools.py	(revision 77804)
+++ Lib/test/test_functools.py	(working copy)
@@ -7,6 +7,14 @@
 @staticmethod
 def PythonPartial(func, *args, **keywords):
     'Pure Python approximation of partial()'
+    if hasattr(func, 'func'):
+        args = func.args + args
+        tmpkw = func.keywords.copy()
+        tmpkw.update(keywords)
+        keywords = tmpkw
+        del tmpkw
+        func = func.func
+
     def newfunc(*fargs, **fkeywords):
         newkeywords = keywords.copy()
         newkeywords.update(fkeywords)
@@ -123,7 +131,7 @@
         self.assertRaises(ZeroDivisionError, self.thetype(f, y=0), 1)
 
     def test_attributes(self):
-        p = self.thetype(hex)
+        p = self.thetype(hex, 1)
         try:
             del p.__dict__
         except TypeError:
@@ -151,6 +159,12 @@
         f_copy = pickle.loads(pickle.dumps(f))
         self.assertEqual(signature(f), signature(f_copy))
 
+    def test_nested(self):
+        partial = self.thetype
+        f = partial(partial(signature, 'asdf'), bar=True)
+        g = partial(signature, 'asdf', bar=True)
+        self.assertEqual(signature(f), signature(g))
+
 class PartialSubclass(functools.partial):
     pass
 
@@ -158,6 +172,12 @@
 
     thetype = PartialSubclass
 
+    def test_nested(self):
+        partial = self.thetype
+        f = partial(signature, 'asdf')
+        g = partial(f, bar=True)
+        self.assertEqual(signature(g), (f, (), {'bar': True}, {}))
+
 class TestPythonPartial(TestPartial):
 
     thetype = PythonPartial
Index: Modules/_functoolsmodule.c
===================================================================
--- Modules/_functoolsmodule.c	(revision 77804)
+++ Modules/_functoolsmodule.c	(working copy)
@@ -103,7 +103,7 @@
 static PyObject *
 partial_new(PyTypeObject *type, PyObject *args, PyObject *kw)
 {
-	PyObject *func;
+	PyObject *func, *pargs, *nargs, *pkw;
 	partialobject *pto;
 
 	if (PyTuple_GET_SIZE(args) < 1) {
@@ -113,6 +113,15 @@
 	}
 
 	func = PyTuple_GET_ITEM(args, 0);
+	if (Py_TYPE(func) == &partial_type && type ==  &partial_type) {
+		pargs = ((partialobject *)func)->args;
+		pkw = ((partialobject *)func)->kw;
+		func = ((partialobject *)func)->fn;
+	} else {
+		pargs = Py_None;
+		pkw = Py_None;
+
+	}
 	if (!PyCallable_Check(func)) {
 		PyErr_SetString(PyExc_TypeError,
 				"the first argument must be callable");
@@ -126,21 +135,49 @@
 
 	pto->fn = func;
 	Py_INCREF(func);
-	pto->args = PyTuple_GetSlice(args, 1, PY_SSIZE_T_MAX);
-	if (pto->args == NULL) {
+
+	nargs = PyTuple_GetSlice(args, 1, PY_SSIZE_T_MAX);
+	if (nargs == NULL) {
+		pto->args = NULL;
 		pto->kw = NULL;
 		Py_DECREF(pto);
 		return NULL;
 	}
+	if (pargs == Py_None || PyTuple_GET_SIZE(pargs) == 0) {
+		pto->args = nargs;
+		Py_INCREF(nargs);
+	} else if (PyTuple_GET_SIZE(nargs) == 0) {
+		pto->args = pargs;
+		Py_INCREF(pargs);
+	} else {
+		pto->args = PySequence_Concat(pargs, nargs);
+		if (pto->args == NULL) {
+			pto->kw = NULL;
+			Py_DECREF(pto);
+			return NULL;
+		}
+	}
+	Py_DECREF(nargs);
+
 	if (kw != NULL) {
-		pto->kw = PyDict_Copy(kw);
+		if (pkw == Py_None) {
+			pto->kw = PyDict_Copy(kw);
+		} else {
+			pto->kw = PyDict_Copy(pkw);
+			if (pto->kw != NULL) {
+				if (PyDict_Merge(pto->kw, kw, 1) != 0) {
+					Py_DECREF(pto);
+					return NULL;
+				}
+			}
+		}
 		if (pto->kw == NULL) {
 			Py_DECREF(pto);
 			return NULL;
 		}
 	} else {
-		pto->kw = Py_None;
-		Py_INCREF(Py_None);
+		pto->kw = pkw;
+		Py_INCREF(pkw);
 	}
 
 	pto->weakreflist = NULL;