.

go/zodb/persistent.go

@@ -416,6 +416,7 @@ func newGhost(class string, oid Oid, jar *Connection) IPersistent {
 	var xpobj reflect.Value // *typ
 	zc := classTab[class]
 	if zc == nil {
+		zc = brokenZClass
 		xpobj = reflect.ValueOf(&Broken{class: class})
 	} else {
 		xpobj = reflect.New(zc.typ)
@@ -423,6 +424,7 @@ func newGhost(class string, oid Oid, jar *Connection) IPersistent {
 
 	xobj  := xpobj.Elem() // typ
 	pbase := xobj.FieldByName("Persistent").Addr().Interface().(*Persistent)
+	pbase.zclass = zc
 	pbase.jar = jar
 	pbase.oid = oid
 	pbase.serial = 0
@@ -458,3 +460,10 @@ func (b *brokenState) SetState(state *mem.Buf) error	{
 	b.state = state
 	return nil
 }
+
+// brokenZClass is used for Persistent.zclass for Broken objects.
+var brokenZClass = &zclass{
+	class:		"",
+	typ:		reflect.TypeOf(Broken{}),
+	stateType:	reflect.TypeOf(brokenState{}),
+}

go/zodb/persistent_test.go

@@ -61,15 +61,23 @@ func TestPersistent(t *testing.T) {
 
 	// checkObj verifies current state of persistent object.
 	checkObj := func(obj IPersistent, jar *Connection, oid Oid, serial Tid, state ObjectState, refcnt int32, loading *loadState) {
+		t.Helper()
 		xbase := reflect.ValueOf(obj).Elem().FieldByName("Persistent")
 		pbase := xbase.Addr().Interface().(*Persistent)
 
 		badf := func(format string, argv ...interface{}) {
+			t.Helper()
 			msg := fmt.Sprintf(format, argv...)
 			t.Fatalf("%#v: %s", obj, msg)
 		}
 
-		// XXX .zclass ?
+		zc := pbase.zclass
+		//zc.class
+		if typ := reflect.TypeOf(obj).Elem(); typ != zc.typ {
+			badf("invalid zclass: .typ = %s  ; want %s", zc.typ, typ)
+		}
+		//zc.stateType
+
 		if pbase.jar != jar {
 			badf("invalid jar")
 		}