Fixes type system for QAbstractTransition.setTargetState.

And also for QAbstractTransition.targetState method.
The test cases for it were expanded.

tests/qtcore/qabstracttransition_test.py

@@ -1,6 +1,8 @@
 #!/usr/bin/python
 import unittest
-from PySide.QtCore import QObject, QState, QFinalState, SIGNAL, QCoreApplication, QTimer, QStateMachine, QSignalTransition, QVariant, QParallelAnimationGroup
+from sys import getrefcount
+from PySide.QtCore import QObject, SIGNAL, QCoreApplication, QTimer, QVariant
+from PySide.QtCore import QState, QFinalState, QStateMachine, QParallelAnimationGroup, QEventTransition
 
 def addStates(transition):
     sx = QState()
@@ -47,5 +49,24 @@ class QAbstractTransitionTest(unittest.TestCase):
         QTimer.singleShot(100, app.quit)
         app.exec_()
 
+    def testRefCountOfTargetState(self):
+        transition = QEventTransition()
+        state1 = QState()
+        refcount1 = getrefcount(state1)
+        transition.setTargetState(state1)
+        self.assertEqual(transition.targetState(), state1)
+        self.assertEqual(getrefcount(transition.targetState()), refcount1 + 1)
+
+        state2 = QState()
+        refcount2 = getrefcount(state2)
+        transition.setTargetState(state2)
+        self.assertEqual(transition.targetState(), state2)
+        self.assertEqual(getrefcount(transition.targetState()), refcount2 + 1)
+        self.assertEqual(getrefcount(state1), refcount1)
+
+        del transition
+        self.assertEqual(getrefcount(state2), refcount2)
+
 if __name__ == '__main__':
     unittest.main()
+