gracefully handle deletion of transition's target state

1 files changed, 14 insertions, 2 deletions

diff --git a/src/corelib/statemachine/qabstracttransition.cpp b/src/corelib/statemachine/qabstracttransition.cpp
index 696da9f..6ddb416 100644
--- a/src/corelib/statemachine/qabstracttransition.cpp
+++ b/src/corelib/statemachine/qabstracttransition.cpp
@@ -273,7 +273,13 @@ void QAbstractTransition::setTargetState(QAbstractState* target)
 QList<QAbstractState*> QAbstractTransition::targetStates() const
 {
     Q_D(const QAbstractTransition);
-    return d->targetStates;
+    QList<QAbstractState*> result;
+    for (int i = 0; i < d->targetStates.size(); ++i) {
+        QAbstractState *target = d->targetStates.at(i);
+        if (target)
+            result.append(target);
+    }
+    return result;
 }
 
 /*!
@@ -285,13 +291,19 @@ void QAbstractTransition::setTargetStates(const QList<QAbstractState*> &targets)
 
     for (int i=0; i<targets.size(); ++i) {
         QAbstractState *target = targets.at(i);
+        if (!target) {
+            qWarning("QAbstractTransition::setTargetStates: target state(s) cannot be null");
+            return;
+        }
         if (target->machine() != 0 && target->machine()->rootState() == target) {
             qWarning("QAbstractTransition::setTargetStates: root state cannot be target of transition");
             return;
         }
     }
 
-    d->targetStates = targets;
+    d->targetStates.clear();
+    for (int i = 0; i < targets.size(); ++i)
+        d->targetStates.append(targets.at(i));
 }
 
 /*!