Fixes from Neal Norwitz, plus other small fixes.

Modules/_ctypes/_ctypes.c

@@ -285,6 +285,7 @@ CDataType_from_param(PyObject *type, PyObject *value)
 	if (PyCArg_CheckExact(value)) {
 		PyCArgObject *p = (PyCArgObject *)value;
 		PyObject *ob = p->obj;
+		const char *ob_name;
 		StgDictObject *dict;
 		dict = PyType_stgdict(type);
 
@@ -296,10 +297,10 @@ CDataType_from_param(PyObject *type, PyObject *value)
 			Py_INCREF(value);
 			return value;
 		}
+		ob_name = (ob) ? ob->ob_type->tp_name : "???";
 		PyErr_Format(PyExc_TypeError,
 			     "expected %s instance instead of pointer to %s",
-			     ((PyTypeObject *)type)->tp_name,
-			     ob->ob_type->tp_name);
+			     ((PyTypeObject *)type)->tp_name, ob_name);
 		return NULL;
 	}
 #if 1
@@ -506,12 +507,12 @@ size property/method, and the sequence protocol.
 static int
 PointerType_SetProto(StgDictObject *stgdict, PyObject *proto)
 {
-	if (proto && !PyType_Check(proto)) {
+	if (!proto || !PyType_Check(proto)) {
 		PyErr_SetString(PyExc_TypeError,
 				"_type_ must be a type");
 		return -1;
 	}
-	if (proto && !PyType_stgdict(proto)) {
+	if (!PyType_stgdict(proto)) {
 		PyErr_SetString(PyExc_TypeError,
 				"_type_ must have storage info");
 		return -1;
@@ -1264,10 +1265,14 @@ static PyObject *CreateSwappedType(PyTypeObject *type, PyObject *args, PyObject
 	PyTypeObject *result;
 	StgDictObject *stgdict;
 	PyObject *name = PyTuple_GET_ITEM(args, 0);
-	PyObject *swapped_args = PyTuple_New(PyTuple_GET_SIZE(args));
+	PyObject *swapped_args;
 	static PyObject *suffix;
 	int i;
 
+	swapped_args = PyTuple_New(PyTuple_GET_SIZE(args));
+	if (!swapped_args)
+		return NULL;
+
 	if (suffix == NULL)
 #ifdef WORDS_BIGENDIAN
 		suffix = PyString_FromString("_le");
@@ -2781,7 +2786,7 @@ _get_arg(int *pindex, char *name, PyObject *defval, PyObject *inargs, PyObject *
 static PyObject *
 _build_callargs(CFuncPtrObject *self, PyObject *argtypes,
 		PyObject *inargs, PyObject *kwds,
-		int *poutmask, int *pinoutmask, int *pnumretvals)
+		int *poutmask, int *pinoutmask, unsigned int *pnumretvals)
 {
 	PyObject *paramflags = self->paramflags;
 	PyObject *callargs;
@@ -2836,6 +2841,7 @@ _build_callargs(CFuncPtrObject *self, PyObject *argtypes,
 		switch (flag & (PARAMFLAG_FIN | PARAMFLAG_FOUT | PARAMFLAG_FLCID)) {
 		case PARAMFLAG_FIN | PARAMFLAG_FLCID:
 			/* ['in', 'lcid'] parameter.  Always taken from defval */
+			assert(defval);
 			Py_INCREF(defval);
 			PyTuple_SET_ITEM(callargs, i, defval);
 			break;
@@ -2939,9 +2945,10 @@ _build_callargs(CFuncPtrObject *self, PyObject *argtypes,
 */
 static PyObject *
 _build_result(PyObject *result, PyObject *callargs,
-	      int outmask, int inoutmask, int numretvals)
+	      int outmask, int inoutmask, unsigned int numretvals)
 {
-	int i, index, bit;
+	unsigned int i, index;
+	int bit;
 	PyObject *tup = NULL;
 
 	if (callargs == NULL)
@@ -2952,6 +2959,7 @@ _build_result(PyObject *result, PyObject *callargs,
 	}
 	Py_DECREF(result);
 
+	/* tup will not be allocated if numretvals == 1 */
 	/* allocate tuple to hold the result */
 	if (numretvals > 1) {
 		tup = PyTuple_New(numretvals);
@@ -3275,6 +3283,8 @@ Struct_init(PyObject *self, PyObject *args, PyObject *kwds)
 		if (!fields) {
 			PyErr_Clear();
 			fields = PyTuple_New(0);
+			if (!fields)
+				return -1;
 		}
 
 		if (PyTuple_GET_SIZE(args) > PySequence_Length(fields)) {