Pasting a list item into the middle of another list item should split the target list item into two with the pasted content in between.

one two: one two
three: three
one two: one two
:
four: four
monsters walking: <span style="background-color:green"><b>monsters walking</b></span>
one two: one two
:
cross the floor: <span style="background-color:green"><b>cross the floor</b></span>
PASS


