From a bug report, being stuck in the
floor or in lava and trying to move downwards while levitating gave "you
are floating high above the floor/lava" which contradicts being stuck.
Now you'll get "you are trapped in the floor/lava" in that situation.
I thought about letting it fall through to the chance to autodig with
wielded pick, but decided to go with just the alternate message. (Being
tethered to a buried iron ball still lets you "float high above the floor",
so this doesn't check for being trapped that way.)
projects / nethack / commit