The body of this document is scrollable and is the main scrollable
element. On top of that we have a hidden fixed-pos item containing another
scrollframe, but this nested scrollframe is inactive.
Since the fixed-pos item is hidden, the nested scrollframe is hidden
too and shouldn't be the target of hit-testing. However, because it is
an inactive scrollframe, code to generate the "this is an inactive
scrollframe" area was marking it as hit-testable. This bug led to hit-
tests being mis-targeted to the nested scrollframe's layers id instead
of whatever was underneath.