statemachine: Don't crash if property assignment target is deleted

Do like QPropertyAnimation and store the QObject in a QPointer.
Purge the assignments list upon state entry and property restore.

Change-Id: I54a56885a2905178ab6aa5cf292b3d25c86b7a97
Reviewed-by: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@nokia.com>

1 files changed, 5 insertions, 1 deletions

diff --git a/src/corelib/statemachine/qstate_p.h b/src/corelib/statemachine/qstate_p.h
index 30be47cf51..9558bd88a5 100644
--- a/src/corelib/statemachine/qstate_p.h
+++ b/src/corelib/statemachine/qstate_p.h
@@ -57,6 +57,7 @@
 
 #include <QtCore/qlist.h>
 #include <QtCore/qbytearray.h>
+#include <QtCore/qpointer.h>
 #include <QtCore/qvariant.h>
 
 QT_BEGIN_NAMESPACE
@@ -69,7 +70,10 @@ struct QPropertyAssignment
                         const QVariant &v, bool es = true)
         : object(o), propertyName(n), value(v), explicitlySet(es)
         {}
-    QObject *object;
+
+    bool objectDeleted() const { return !object; }
+
+    QPointer<QObject> object;
     QByteArray propertyName;
     QVariant value;
     bool explicitlySet;