Index: core/PyFunction.java
===================================================================
RCS file: /cvsroot/jython/jython/org/python/core/PyFunction.java,v
retrieving revision 2.16
diff -u -r2.16 PyFunction.java
--- core/PyFunction.java	6 Aug 2003 11:46:25 -0000	2.16
+++ core/PyFunction.java	24 Feb 2004 20:33:58 -0000
@@ -27,10 +27,9 @@
         func_defaults = defaults;
         func_code = code;
         if (closure_cells != null) {
-            func_closure = new PyTuple(closure_cells);
-        } else {
-            func_closure = null;
-        }
+        	func_closure = new PyTuple(closure_cells);
+        } // else func_closure is already null; no extra assignment needed
+		validateClosure(func_closure);
     }
 
     public PyFunction(PyObject globals, PyObject[] defaults, PyCode code,
@@ -72,17 +71,48 @@
                 throw Py.TypeError("readonly attribute");
         throw Py.AttributeError(name);
     }
-
+    
+    private void validateClosureCell(PyObject o) {
+    	if (!(o instanceof PyCell)) {
+    		throw Py.TypeError("(closure) expected cell, found " + o.__class__.__name__);
+    	}
+    }
+    
+    private void validateClosureSize(int size)
+    {
+		if (func_code instanceof PyTableCode) {
+			String[] freevars = ((PyTableCode)func_code).co_freevars;
+			int expectedSize = (freevars == null) ? 0 : freevars.length;
+			if (size != expectedSize) {
+				throw Py.ValueError(
+					func_code.co_name
+					+ " requires closure of length " + expectedSize
+					+ ", not " + size);
+			}
+		}
+    }
+    
+    private void validateClosure(PyObject o) {
+    	if ((o == null )) {
+    		validateClosureSize(0);
+    		return;
+    	}
+
+		if (!(o instanceof PyTuple)) {
+			throw Py.TypeError("(closure) must be tuple");
+		}
+		PyTuple t = (PyTuple)o;
+		validateClosureSize(t.__len__());
+		for (int i = 0; i < t.__len__(); i++) {
+			validateClosureCell(t.get(i));
+		}
+    }
+    
     public void __setattr__(String name, PyObject value) {
-        // TBD: in CPython, func_code, func_defaults, func_doc, __doc__ are
-        // writable.  For now, only func_doc, __doc__ are writable in
-        // JPython.
         if (name == "func_doc" || name == "__doc__")
             __doc__ = value;
         else if (name == "func_closure") {
-            if (!(value instanceof PyTuple)) {
-                throw Py.TypeError("func_closure must be set to a tuple");
-            }
+        	validateClosure(value);
             func_closure = value;
         }
         // not yet implemented:
Index: modules/newmodule.java
===================================================================
RCS file: /cvsroot/jython/jython/org/python/modules/newmodule.java,v
retrieving revision 1.4
diff -u -r1.4 newmodule.java
--- modules/newmodule.java	11 Jul 2003 22:14:14 -0000	1.4
+++ modules/newmodule.java	24 Feb 2004 20:33:58 -0000
@@ -41,12 +41,8 @@
     public static PyFunction function(PyCode code, PyObject globals,
                                       String name, PyObject[] argdefs)
     {
-        PyFunction f = new PyFunction(globals, argdefs, code, null,null);
-        if (name != null)
-            f.__name__ = name;
-        return f;
+        return function(code, globals, name, argdefs, null);
     }
-
 
     public static PyFunction function(PyCode code, PyObject globals,
                                       String name, PyObject[] argdefs,