Blender Git Loki

Fix T74889 Baking to current action doesn't work properly

Before this commit, baking an action would only insert keys that are
necessary (i.e. using `INSERTKEY_NEEDED`). When baking to the current
Action, if there are no constraints that influence the final animation,
there are no additional keys necessary. This makes it appear as if
nothing happened. However, when baking to a new Action every additional
frame is necessary and thus a key is added for every frame.

@mont29 and I agreed that this behaviour is confusing, so this commit
changes the behaviour such that baking to the current action and to a
new action result in the same baked animation (that is, keyed on every
frame).