ScxmlEditor: Fix a crash when closing scxml editor

Don't iterate on m_overlappedItems inside d'tor, as every
iteration calls removeOverlappingItem() and it modifies
the container being iterated. Do the same for m_outputTransitions
and m_inputTransitions.

Amends 8b444f88eb

Fixes: QTCREATORBUG-28027
Change-Id: I78fe67b5ea584c969e4850a2db3f00d981296865
Reviewed-by: <github-actions-qt-creator@cristianadam.eu>
Reviewed-by: Artem Sokolovskii <artem.sokolovskii@qt.io>
Reviewed-by: Alessandro Portale <alessandro.portale@qt.io>

src/plugins/scxmleditor/plugin_interface/connectableitem.cpp

@@ -64,15 +64,18 @@ ConnectableItem::~ConnectableItem()
 {
     setBlockUpdates(true);
 
-    for (ConnectableItem *item : qAsConst(m_overlappedItems))
+    const QList<ConnectableItem *> overlappedItems = m_overlappedItems;
+    for (ConnectableItem *item : overlappedItems)
         item->removeOverlappingItem(this);
     m_overlappedItems.clear();
 
-    for (TransitionItem *transition : qAsConst(m_outputTransitions))
+    const QList<TransitionItem *> outputTransitions = m_outputTransitions;
+    for (TransitionItem *transition : outputTransitions)
         transition->disconnectItem(this);
     m_outputTransitions.clear();
 
-    for (TransitionItem *transition : qAsConst(m_inputTransitions))
+    const QList<TransitionItem *> inputTransitions = m_inputTransitions;
+    for (TransitionItem *transition : inputTransitions)
         transition->disconnectItem(this);
     m_inputTransitions.clear();
 
@@ -310,7 +313,8 @@ void ConnectableItem::updateTransitions(bool allChildren)
     updateInputTransitions();
 
     if (allChildren) {
-        for (QGraphicsItem *it : childItems()) {
+        const QList<QGraphicsItem *> items = childItems();
+        for (QGraphicsItem *it : items) {
             auto item = static_cast<ConnectableItem*>(it);
             if (item && item->type() >= InitialStateType)
                 item->updateTransitions(allChildren);

src/plugins/scxmleditor/plugin_interface/scattributeitemdelegate.cpp

@@ -80,7 +80,7 @@ void SCAttributeItemDelegate::setEditorData(QWidget *editor, const QModelIndex &
             combo->clear();
             const QStringList values = index.data(DataRole).toString().split(";");
 
-            for (QString val : values)
+            for (const QString &val : values)
                 combo->addItem(val);
 
             combo->setCurrentText(index.data().toString());