Would it make the UI more consistent if ACTION_TREE_STOP, which as best I can tell just means 'stop playing music whilst in a menu', and seems to ultimately call 'list_stop_handler' in apps/misc.c, stopped the radio as well as any local file which might be playing?
ETA- To clarify slightly, it just seems strange that if you drop out of the WPS into a menu, then hit a key assigned to ACTION_TREE_STOP, it stops, whereas if you drop out of the Radio screen and do the same, it ignores you.
I had a look at patching this myself, but there seems to be too much separation between radio.c and the general interface handling code for a non-coder to deal with...