if the first visual item is the second element in model (whose index is 1), insert new element at position 0 will not affect visual items.

but if the first visual item is the first element in model, same operation will result in auto scrolling down. (the number of elements in model is enough more than one screen to display)

after check the code, (I don't know if I had found the right position):

file: qtdeclarative/src/quick/items/qquicklistview.cpp
function: bool QQuickListViewPrivate::applyInsertionChange

sentence:  if (insertResult->visiblePos.isValid() && pos < insertResult->visiblePos) {

does the "pos < insertResult->visiblePos" should be "pos <= insertResult->visiblePos" ???