Failure of auto-cancel of LI upon cancel of last copy not always detected

[Galen Charlton]

Consider a purchase order that has a line item with one line item copy. Suppose that the user cancels the line item copy. Doing that should trigger cancelling the line item itself (see bug 978095).

However, if the line item cancellation fails (e.g., if cancelling the line item should delete real item records, but the staff user doesn't have the DELETE_COPY permission), there is no direct indication that something went wrong. Instead, the line item copy shows as cancelled while the line item shows as still on-order.

I think it would be better if a failure to auto-cancel the line item prevents the cancellation of the line item copy with a suitable error message. At the very least, a warning should be displayed.

For anybody taking on this bug, note that the return value of autocancel_lineitem() in Open-ILS/src/perlmods/lib/OpenILS/Application/Acq/Order.pm is not checked to see if it might be a failure event.

Evergreen master