https://github.com/bitcoin/bitcoin/blob/5180a86c96bc05d2a731f70f36aae28ab5a3fad4/src/qt/sendcoinsdialog.cpp#L339

I think this is %1, not %2
{
    SendCoinsEntry *entry = 0;
    
    if(ui->entries->count() == 1)
    {
        SendCoinsEntry *first = qobject_cast<SendCoinsEntry*>(ui->entries->itemAt(0)->widget());
        if(first->isClear())
        {
            entry = first;
        }
    }
    if(!entry)
    {
        entry = addEntry();
    }
    entry->setAddress(address);
}
void SendCoinsDialog::pasteEntry(const SendCoinsRecipient &rv)