Renaming a price option / fee level breaks event participant lists

Renaming a price option associated with an event, after some people have booked it, breaks participant lists.

Steps to reproduce: http://dmaster.demo.civicrm.org/

Create a new priceset: Events > Manage pricesets
Set name 'Test priceset', used for events, event fees
Add a field 'Price field' with the input type 'Checkboxes'

• Add a new option 'Foo', amount: 1, Max participants: 1, save

Create a new event
Fees > Enable pay later and assign the priceset we just created
Online registration > Enable, default settings

Register for the event, selecting the 'Foo' price option

Manage pricesets, edit the field, edit the options, rename the 'Foo' option label to 'Bar'

Go to register for the event again

Notice that the price option has been renamed, and is sold out (expected behaviour)

Event > Find participants
Choose 'Bar' as a 'Fee Level'
No participants found - ERROR

Display all participants for the event, 'Foo' is still listed in the fee level box - ERROR

Problem

It looks like the fee level / price options are stored as strings in the database against a participation - perhaps this is confusing the logic on reporting. Not sure how the booking form still knows that the option is sold out though.