Missing items in ILS not detected properly

[aw-bib]

For generation of the Holdings-tab invenio checks if all items are set to status missing. If all items are missing the display changes to a link for the ILL subsystem to enable patrons to order items. As long as only one item is associated with a record, this works fine. However, if more than one item is associated with a given record the ILL-display is wrongly triggered. The error stems from get_copies_status() in bibcirculation_dblayer. Though the name suggests that it returns the status of all copies it effectifely returns res[0], ie. the status of exactly one copy.

This function is only used all_copies_are_missing() and has_copies() within bibcirculation_utils.

[aw-bib]

Addresses: join2/join2#1059