Index: marshal.c
===================================================================
RCS file: /cvsroot/python/python/dist/src/Python/marshal.c,v
retrieving revision 1.47
diff -u -r1.47 marshal.c
--- marshal.c	2000/05/03 23:44:39	1.47
+++ marshal.c	2000/06/19 00:18:44
@@ -58,6 +58,7 @@
 typedef struct {
 	FILE *fp;
 	int error;
+	int depth;
 	/* If fp == NULL, the following are valid: */
 	PyObject *str;
 	char *ptr;
@@ -144,8 +145,13 @@
 {
 	int i, n;
 	PyBufferProcs *pb;
+
+	p->depth++;
 	
-	if (v == NULL) {
+	if (p->depth > 5000) {
+		p->error = 2;
+	} 
+	else if (v == NULL) {
 		w_byte(TYPE_NULL, p);
 	}
 	else if (v == Py_None) {
@@ -301,6 +307,7 @@
 	WFILE wf;
 	wf.fp = fp;
 	wf.error = 0;
+	wf.depth = 0;
 	w_long(x, &wf);
 }
 
@@ -690,6 +697,7 @@
 	wf.ptr = PyString_AS_STRING((PyStringObject *)wf.str);
 	wf.end = wf.ptr + PyString_Size(wf.str);
 	wf.error = 0;
+	wf.depth = 0;
 	w_object(x, &wf);
 	if (wf.str != NULL)
 		_PyString_Resize(&wf.str,
@@ -697,7 +705,9 @@
 			   PyString_AS_STRING((PyStringObject *)wf.str)));
 	if (wf.error) {
 		Py_XDECREF(wf.str);
-		PyErr_SetString(PyExc_ValueError, "unmarshallable object");
+		PyErr_SetString(PyExc_ValueError, 
+				(wf.error==1)?"unmarshallable object"
+				:"object too deeply nested to marshal");
 		return NULL;
 	}
 	return wf.str;
@@ -724,9 +734,12 @@
 	wf.str = NULL;
 	wf.ptr = wf.end = NULL;
 	wf.error = 0;
+	wf.depth = 0;
 	w_object(x, &wf);
 	if (wf.error) {
-		PyErr_SetString(PyExc_ValueError, "unmarshallable object");
+		PyErr_SetString(PyExc_ValueError, 
+				(wf.error==1)?"unmarshallable object"
+				:"object too deeply nested to marshal");
 		return NULL;
 	}
 	Py_INCREF(Py_None);