Some new points don't inherit any parameters, breaks functionnality

[patrickdupuis]

Reproducer

x = PresetInterpolator(Interpolator(3));
x.cursor.add(); // create one or more basic parameters
x.model.add(); // repeat many times until a new preset without the parameter is created
// notice functionality is broken until the offending preset is deleted 

This is a related error message:

ERROR: Message '*' not understood.
RECEIVER:
   nil
ARGS:
   Float 0.348398   F07D0C48 3FD64C26
CALL STACK:
	DoesNotUnderstandError:reportError
		arg this = <instance of DoesNotUnderstandError>
	Nil:handleError
		arg this = nil
		arg error = <instance of DoesNotUnderstandError>
	Thread:handleError
		arg this = <instance of Thread>
		arg error = <instance of DoesNotUnderstandError>
	Object:throw
		arg this = <instance of DoesNotUnderstandError>
	Object:doesNotUnderstand
		arg this = nil
		arg selector = '*'
		arg args = [*1]
	< FunctionDef in Method Collection:sum >
		arg elem = nil
		arg i = 2
	ArrayedCollection:do
		arg this = [*4]
		arg function = <instance of Function>
		var i = 2
	Collection:sum
		arg this = [*4]
		arg function = <instance of Function>
		var sum = 0
	SequenceableCollection:wmean
		arg this = [*4]
		arg weights = [*4]
	< FunctionDef in Method PresetInterpolator:initActions >
		arg i = <instance of Parameter>
		arg j = 0
	ArrayedCollection:do
		arg this = [*3]
		arg function = <instance of Function>
		var i = 0
	List:do
		arg this = <instance of List>
		arg function = <instance of Function>
	PresetInterpolator:update
		arg this = <instance of PresetInterpolator>
		arg theChanger = <instance of Interpolator>
		arg what = 'weights'
		arg moreArgs = [*2]
		var action = <instance of Function>
	< FunctionDef in Method Set:do >
		arg item = <instance of PresetInterpolator>
	ArrayedCollection:do
		arg this = [*8]
		arg function = <instance of Function>
		var i = 0
	Set:do
		arg this = <instance of IdentitySet>
		arg function = <instance of Function>
		var i = 0
...
^^ The preceding error dump is for ERROR: Message '*' not understood.
RECEIVER: nil