Unit: no battle pad holds both NEXT and BACK, over every sub-state with and
without a potion and a ball, and NEXT is on none with a cursor accepting input
(the assertion the top-level menu failed before this branch). A battle frame
with a cursor accepting input is the fly's turn, against real WRAM, for all
four menus plus the two frames that correctly are not one. The bag deals
ITEM / THROW BALL / BACK, and BACK alone when the bag is empty.
ROM-gated, from the live rung-9 forest checkpoint: no pad with both buttons, no
NEXT while a menu accepts input, the longest NEXT/BACK alternation under four,
and every battle entered also left, each on a bounded number of macros. The
battle rules ask the scene the pad was dealt for rather than wIsInBattle, so
the $ff frame a lost battle passes through -- which reads Unknown, whose pad is
NEXT and BACK by contract -- is not accused of a battle rule.
The test fails on v0.4.2 from the same checkpoint with "NEXT was on the pad
while a battle menu was accepting input", NEXT dealt on battle/main, and a run
that never leaves map 51.