c++ - Sorting QComboBox delete data in UserRole -

i have problem custom data in qcombo box , here minimal example, empty project qcombobox named combobox in ui. here c'tor code:

ui->setupui(this);  //add sort proxy qsortfilterproxymodel* proxy = new qsortfilterproxymodel(ui->combobox); proxy->setsourcemodel(ui->combobox->model()); ui->combobox->model()->setparent(proxy); ui->combobox->setmodel(proxy);  //first strange thing //here first additem triggers current index changed signal //in second run, every additem trigger signal   qdebug() << "initializing"; for( size_t i=1; i<1e10; i*=10 )     ui->combobox->additem( "item",  );  qdebug() << "sorting"; proxy->sort(0); proxy->sort(0);  qdebug() << "selecting"; ui->combobox->setcurrentindex(0);   //here fine   for( int i=0; i<ui->combobox->count(); ++i )     qdebug() << ui->combobox->itemdata(i).value<size_t>();    //clear box , same again!  ui->combobox->clear();  //now every additem triggers current changed event qdebug() << "initializing"; for( size_t i=1; i<1e10; i*=10 )     ui->combobox->additem( "item",  );  qdebug() << "sorting"; proxy->sort(0);  qdebug() << "selecting"; ui->combobox->setcurrentindex(0);   //here itemdata values 0!!!   for( int i=0; i<ui->combobox->count(); ++i )     qdebug() << ui->combobox->itemdata(i).value<size_t>(); 

and here slot

void mainwindow::on_combobox_currentindexchanged(int index) {     qdebug() << "current changed " << index;     qdebug() << "userrole " << ui->combobox->itemdata(index); } 

the second time add items calls current index changed event every time, first time on first additem.

in second run, after sort, user data 0.

any ideas?

this (http://www.qtcentre.org/threads/3741-how-to-sort-a-qcombobox-in-qt4) post suggest bug. 10 years old know im getting same error. if remove first sort(0) data doesn't disappear. maybe make custom insert function items insert in correct order.

ui->combobox->setinsertpolicy(qcombobox::insertalphabetically); 

but lessthan behaviour.