Clef change following spine split after first note of measure

[bel28kent]

When a spine is split into subspines after the first note of a measure, and that split is then followed by a clef change, the clef change is only applied to one of the subspines (m. 1 of example). m. 2 of example shows that the clef change is not problematic when the spine split is at the beginning of the measure (though it necessitates an added hidden rest).

**kern
*staff1
*clefG2
*k[]
*M2/4
=-1
4a
*^
*clefF4	*clefF4
4a	4A
*v	*v
*clefG2
=2
*^
4a	4ryy
*clefF4	*clefF4
4a	4A
*v	*v
=
*-