It looks like all that is necessary to fix this is to lowercase the user input before comparing.
I've attached a patch that fixes this for me with bzr 1.16.1. With the change it works for variations like Y as well as Yes, YES, and YeS.
It might be desirable to add uppercase Yes and No to the tests of the get_boolean function in tests/test_ui.py.
It looks like all that is necessary to fix this is to lowercase the user input before comparing.
I've attached a patch that fixes this for me with bzr 1.16.1. With the change it works for variations like Y as well as Yes, YES, and YeS.
It might be desirable to add uppercase Yes and No to the tests of the get_boolean function in tests/test_ui.py.