.

go/zodb/persistent.go

@@ -383,7 +383,7 @@ func RegisterClass(class string, typ, stateType reflect.Type) {
 //
 // Class aliases are useful for backward compatibility - sometimes class name
 // of an object changes, but to support loading previously-saved objects, the
-// old class name have to be also supported.
+// old class name has to be also supported.
 func RegisterClassAlias(alias, class string) {
 	badf := func(format string, argv ...interface{}) {
 		msg := fmt.Sprintf(format, argv...)

go/zodb/persistent_test.go

@@ -54,6 +54,7 @@ func (o *myObjectState) PySetState(pystate interface{}) error {
 func init() {
 	t := reflect.TypeOf
 	RegisterClass("t.zodb.MyObject", t(MyObject{}), t(myObjectState{}))
+	RegisterClassAlias("t.zodb.MyOldObject", "t.zodb.MyObject")
 }
 
 func TestPersistent(t *testing.T) {
@@ -115,11 +116,20 @@ func TestPersistent(t *testing.T) {
 	xobj = newGhost("t.zodb.MyObject", 11, nil)
 	obj, ok := xobj.(*MyObject)
 	if !ok {
-		t.Fatalf("unknown -> %T;  want Broken", xobj)
+		t.Fatalf("t.zodb.MyObject -> %T;  want MyObject", xobj)
 	}
 
 	checkObj(obj, nil, 11, InvalidTid, GHOST, 0, nil)
+	assert.Equal(ClassOf(obj), "t.zodb.MyObject")
+
+	// t.zodb.MyOldObject -> *MyObject
+	xobj = newGhost("t.zodb.MyOldObject", 12, nil)
+	obj, ok = xobj.(*MyObject)
+	if !ok {
+		t.Fatalf("t.zodb.MyOldObject -> %T;  want MyObject", xobj)
+	}
 
+	checkObj(obj, nil, 12, InvalidTid, GHOST, 0, nil)
 	assert.Equal(ClassOf(obj), "t.zodb.MyObject")