I have a strange behaviour with a form (mapped to an array, not to a Entity) containing a field of type EntityType with multiple=true.

If I set that field with initial data an empty array, e.g. array(), after successful submit when I call $form->getData() I get an ArrayCollection for that field.

Instead, if I set that field with initial data a non empty array, after a successful submit when I call $form->getData() I get a simple array for that field.

Shouldn't I obtain always the same type?