Non-deductible contribution amounts are always $0

Create an event with a price set which contains two price fields. One price field contains items of financial type "Event Fee" which is defined as non-deductible. The other price field contains items of financial type "Donation" which is defined as deductible.

The Financial Type of the Event, specified on the Fees page, is Donation (although setting it to Event does not change the result).

When a participant registers and selects for example a $30 Event Fee option and a $100 Donation option, a contribution is created which shows the two line items with a net amount of $130 as expected. The non-deductible amount, however, is shown as $0, rather than $30 as I would have expected.

PS: Joe Murray responded on Stack Exchange "Please create an issue on JIRA and assign it to me so I can have my staff look into this", but I am unable (or don't know how) to make that assignment.