The issue is that certain RNA paths cannot be generated to come
from an ID and `RNA_path_from_ID_to_property` will return no value.
We are using that function in the keyframing code to allow passing
in a pointer to a bone and a path relative to that bone.
Since there is currently no good way to find the path from the ID to an arbitrary
struct pointer (see #122427), this patch is a workaround that uses
the struct_pointer IF that happens to be an ID pointer.
Of course that still has the core limitation in place but until a
better solution is available on the RNA side this is the best we can do.
Pull Request: https://projects.blender.org/blender/blender/pulls/132552
2d1fc1bcdd