Caused by 0f5dd1c55c
The refactor commit changed the arguments to receive a `Listbase` reference
instead of a pointer because in all use cases it was always passed.
As such the check for a `ListBase` null pointer went away.
However by removing JUST the nullptr check in this line
`if ((curves) || (flags & ACT_TRANS_LOC) == 0)`
to
`if ((flags & ACT_TRANS_LOC) == 0)`
I effectively changed the behavior.
Since `curves` was ALWAYS passed, the second condition never triggered.
With the change, this condition would always trigger, effectively only
adding the first FCurve of either location rotation or scale.
Pull Request: https://projects.blender.org/blender/blender/pulls/126642
69d50b2f4d