QTreeView insertRows via method crushs / direct call works - c++

Question

I have following strange problem.
I've implemented a QAbstractItemModel to the point that I can insert child nodes to the tree view but something strange occurs when I try to add the nodes via the insertRows() method.
First where all is called:
QApplication a(argc, argv);
QResource::registerResource("Qt5Tutorial.rcc");
QTreeView *treeView = new QTreeView();
treeView->show();
Node rootNode("rootNode");
CameraNode childNode0("childNode0", &rootNode);
CameraNode childNode1("childNode1", &rootNode);
LightNode childNode2("childNode2", &rootNode);
CameraNode childNode3("childNode3", &childNode0);
TransformNode childNode4("childNode4", &childNode2);
TransformNode tryNode("potato");
// setup model
ObjectTreeModel model(&rootNode);
treeView->setModel(&model);
// insert directly via the insert child method
// this works!
childNode0.insertChild(1, &tryNode);
// get the QModelIndex of childNode1
// must be passed in the insertRows() method
QModelIndex index(model.index(1, 0, QModelIndex()));
// the output is "childNode1" what is totally right
qDebug() << "index: "<<static_cast<Node*>(index.internalPointer())->getName();
// output see posted beneath
qDebug() << rootNode.log();
// should insert in "childNode1" -> at 0th position and just 1 Node object
// see the method beneath
model.insertRows(0, 1, index);
// if i try to call the method rootNode.log(); now again, it crashes
return a.exec();
This is the output from the rootNode.log() call:
---rootNode
---childNode0
---childNode3
---potato
---childNode1
---childNode2
---childNode4
As you can see the "Potato" Node is correctly inserted.
View an image
http://www10.pic-upload.de/04.01.13/m65huuqq4ruu.png
But once I try to expand the childNode1 node it crashes. But look at the last comment in the code above. As i mentioned -> if i try to output the tree view now (it iterates through all nodes) it crashes.
When the method is called everything seems to be ok - just when i try to expend the tree view it crashes -> the debug output let me think that all should be ok
The actual error message is a access violation when reading at position ... (translated from German - don't know if its called the same in English)
bool ObjectTreeModel::insertRows(int position, int row, const QModelIndex &parent)
{
beginInsertRows(parent, position, position + row - 1);
Node *parentNode = getNode(parent);
qDebug() << "parentName: " << parentNode->getName();
bool success = false;
for(int i = position; i < row; i++)
{
qDebug() << "inside loop";
qDebug() << "position: " << position << "row: " << row;
TransformNode childNode("insertedNode");
success = parentNode->insertChild(i, &childNode);
qDebug() << "success: " << success;
}
endInsertRows();
return success;
}
The debug output for the method above:
getNode: successful
parentName: "childNode1"
inside loop
position: 0 row: 1
called inserchild
success: true
I have no idea why this happens becuase the debug output seems right and it should be basically the same as insert the node directly via the insertChild method.
I hope that someone has an idea why it doesn't work.
Best regards, Michael

Answer 1

Almost everything is correct. Just this two lines not:
TransformNode *childNode = new TransformNode("insertedNode");
success = parentNode->insertChild(i, childNode);