Only trigger state transitons if next_state != old_state

[JoJoJet]

Objective

Fix #8191.

Currently, a state transition will be triggered whenever the NextState resource has a value, even if that "transition" is to the same state as the previous one. This caused surprising/meaningless behavior, such as the existence of an OnTransition { from: A, to: A } schedule.

Solution

State transition schedules now only run if the new state is not equal to the old state. Change detection works the same way, only being triggered when the states compare not equal.

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Changelog

• State transition schedules are no longer run when transitioning to and from the same state.

Migration Guide

State transitions are now only triggered when the exited and entered state differ. This means that if the world is currently in state A, the OnEnter(A) schedule (or OnExit) will no longer be run if you queue up a state transition to the same state A.

[alice-i-cecile]

State transitions are now only triggered when the exited and entered state differ. This means that if the world is currently in state A, the OnEnter(A) schedule (or OnExit) will no longer be run if you queue up a state transition to the same schedule A.

Updated migration guide suggestion for you. The OnTransition schedules don't exist on 0.10 and your sentence was a fragment.