When assigning an Action to an ID, a slot can be automatically
assigned as well. This behaviour is now extended by making untyped
slot identifiers (like `XXSlot`) act as wildcards.
If the last-used slot identifier was 'untyped' (like `XXSlot`), and a
slot with the same name that is specific to the animated ID's type
exists, that slot will be chosen.
Similarly, if the last-used slot identifier was 'typed' (like
`OBSlot`), a slot `OBSlot` does NOT exist, but an untyped slot with
the same name exists (like `XXSlot`), that one will be chosen.
If there is any ambiguity in the matter, the more specific slot is
chosen. In other words, in this case:
- last_slot_identifier = `XXSlot`
- both `XXSlot` and `OBSlot` exist on the Action (where `OB`
represents the ID type of `animated_id`).
the `OBSlot` should be chosen. This means that `XXSlot` NOT being
auto-assigned if there is an alternative. Since untyped slots are
bound on assignment, this design keeps the Action as-is, which means
that the `XXSlot` remains untyped and thus the user is free to assign
this to another ID type if desired.
Pull Request: https://projects.blender.org/blender/blender/pulls/133653
1a35335fcd