diff -r 56cd8111b7f7 -r 41300fa6a67c src/corelib/statemachine/qabstractstate.cpp
--- a/src/corelib/statemachine/qabstractstate.cpp	Tue Jan 26 12:42:25 2010 +0200
+++ b/src/corelib/statemachine/qabstractstate.cpp	Tue Feb 02 00:43:10 2010 +0200
@@ -78,7 +78,8 @@
   function to perform custom processing when the state is exited.
 */
 
-QAbstractStatePrivate::QAbstractStatePrivate()    
+QAbstractStatePrivate::QAbstractStatePrivate(StateType type)
+    : stateType(type), isMachine(false), parentState(0)
 {
 }
 
@@ -87,6 +88,11 @@
     return q->d_func();
 }
 
+const QAbstractStatePrivate *QAbstractStatePrivate::get(const QAbstractState *q)
+{
+    return q->d_func();
+}
+
 QStateMachine *QAbstractStatePrivate::machine() const
 {
     QObject *par = parent;
@@ -126,7 +132,7 @@
   Constructs a new state with the given \a parent state.
 */
 QAbstractState::QAbstractState(QState *parent)
-    : QObject(*new QAbstractStatePrivate, parent)
+    : QObject(*new QAbstractStatePrivate(QAbstractStatePrivate::AbstractState), parent)
 {
 }
 
@@ -150,7 +156,10 @@
 */
 QState *QAbstractState::parentState() const
 {
-    return qobject_cast<QState*>(parent());
+    Q_D(const QAbstractState);
+    if (d->parentState != parent())
+        d->parentState = qobject_cast<QState*>(parent());
+    return d->parentState;
 }
 
 /*!