phoneNumbers.length attribute gets lost when copied to ListModel

I have come across some strangeness using QtContacts 5.0 on Sailfish.

For various reasons partially lost in the mists of time, I copy contacts (or rather a subset of contract roles) from the ContactModel to a a normal ListModel.

One of the roles copied is "phoneNumbers". This has a child property "length" indicating the number of phoneNumbers available for the contact.

phoneNumbers.length is available (defined) direct from the ContactModel, but is undefined when I try to use it from the ListModel. So the console.log in the function appendContact() gives a valid result, but the console.log in populate() gives undefined.

Other properties, including the phone numbers in phoneNumbers are defined when accessed from the ListModel.

Equivalent code works in Haramtatan / Qt 4.7.4 Mobility 1.2

import QtContacts 5.0
.....

ContactModel

{ id: phoneContactsModelInternal }

ListModel {
id: localContactModelInternal
function populate() {
clear();
for (var i = 0; i < phoneContactsModelInternal.contacts.length; i++)

{ appendContact(phoneContactsModelInternal.contacts[i]); console.log("checking number of phoneNumbers: " + localContactModel.get(i).phoneNumbers.length); }

}
function appendContact(contact) {
localContactModel.append(

{"contactId": contact.contactId, "displayLabel": contact.displayLabel.label, "phoneNumbers": contact.phoneNumbers, "phoneNumbersCount": contact.phoneNumbers.length}

);
console.log("appending: " + contact.displayLabel.label + ", numbers: " +
contact.phoneNumbers.length)
}
}