QTreeWidget: item expanded state not preserved if set before inserting

Reproducable with this code exemple.

#include <QtGui>

int main(int argc, char** argv)
{
QApplication a(argc, argv);
QTreeWidget * tw = new QTreeWidget();

QTreeWidgetItem * root = new QTreeWidgetItem();
root->setText(0,"ROOT");
root->setExpanded( true );

for(int i=0;i<10;i++)

{ QTreeWidgetItem *l1 = new QTreeWidgetItem( root ); l1->setText(0,QString("level 1 %1").arg(i)); l1->setExpanded( true ); QTreeWidgetItem *l2 = new QTreeWidgetItem( l1 ); l2->setText(0,QString("level 2 %1").arg(i)); l2->setExpanded( true ); QTreeWidgetItem *l3 = new QTreeWidgetItem( l2 ); l3->setText(0,QString("level 3 %1").arg(i)); }

tw->addTopLevelItem( root );
tw->show();
return a.exec();
}

The expended state is also lost if you remove and then reinsert an item from the tree widget.