Notices on front-end event registration pay later (and test processor)

This appears to be a recent regression.

Sample event configured to allow Pay Later
Go to front-end registration form and select Pay Later
Fill in fields and click Continue
Notice: Undefined index: amount_level in CRM_Event_Form_Registration_Register->postProcess() (line 1065 of /Users/dgg/git/crm_v4.7/CRM/Event/Form/Registration/Register.php).
Notice: Undefined index: amount_level in CRM_Event_Form_Registration_Confirm->buildQuickForm() (line 270 of /Users/dgg/git/crm_v4.7/CRM/Event/Form/Registration/Confirm.php).

Same notices w/ test processor