When moving onto a different terrain type, the logic for whether to
block or unblock levitation and flying (for the case of moving in
or out of walls and solid stone with Passes_walls while levitating)
was correct but the XOR logic for whether to do a status update
because of such a change was incorrect. So stepping from room floor
to furniture or to doorway and vice versa or from corridor to doorway
and vice versa was requesting a status update when there was no need
for one.
Some other code must be requesting a status update when it is needed
for this (or possibly even more often than that?) because the status
line does seem to show the current state of Lev and Fly accurately.
Otherwise this should have been noticed when switch_terrain() was
first implemented.
c8044a202b