QStateMachine: fix some misleading code

The old code creates a RestorableId from the passed (QObject*, QByteArray)
and used it for lookup in a hash table (ok) and as a container for the
(QObject*, QByteArray), satisfying later references to those parameters
from the RestorableId instance instead of using the parameters directly.

Now, RestorableId holds the QObject* in a QPointer, so the code might have
wanted to detect the object being destroyed as part of the operation, BUT:
a) the operation is a read-only one, and b) the code didn't check for
nullness before dereferencing the QObject*.

Fix by moving the creation of the RestorableId into the scope it's used
and otherwise using the parameters directly.

Change-Id: Iaf12f722fe6841ee1a55037fe33a6115aa699aca
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

1 files changed, 2 insertions, 3 deletions

diff --git a/src/corelib/statemachine/qstatemachine.cpp b/src/corelib/statemachine/qstatemachine.cpp
index 69e942d4fd..27c7b077c6 100644
--- a/src/corelib/statemachine/qstatemachine.cpp
+++ b/src/corelib/statemachine/qstatemachine.cpp
@@ -882,11 +882,10 @@ QVariant QStateMachinePrivate::savedValueForRestorable(const QList<QAbstractStat
 #ifdef QSTATEMACHINE_RESTORE_PROPERTIES_DEBUG
     qDebug() << q_func() << ": savedValueForRestorable(" << exitedStates_sorted << object << propertyName << ")";
 #endif
-    RestorableId id(object, propertyName);
     for (int i = exitedStates_sorted.size() - 1; i >= 0; --i) {
         QAbstractState *s = exitedStates_sorted.at(i);
         QHash<RestorableId, QVariant> restorables = registeredRestorablesForState.value(s);
-        QHash<RestorableId, QVariant>::const_iterator it = restorables.constFind(id);
+        QHash<RestorableId, QVariant>::const_iterator it = restorables.constFind(RestorableId(object, propertyName));
         if (it != restorables.constEnd()) {
 #ifdef QSTATEMACHINE_RESTORE_PROPERTIES_DEBUG
             qDebug() << q_func() << ":   using" << it.value() << "from" << s;
@@ -897,7 +896,7 @@ QVariant QStateMachinePrivate::savedValueForRestorable(const QList<QAbstractStat
 #ifdef QSTATEMACHINE_RESTORE_PROPERTIES_DEBUG
     qDebug() << q_func() << ":   falling back to current value";
 #endif
-    return id.first->property(id.second);
+    return object->property(propertyName);
 }
 
 void QStateMachinePrivate::registerRestorable(QAbstractState *state, QObject *object, const QByteArray &propertyName,