If you died in Prize for the Reckless, which is at (11,7), and respawned
in the same room, tile 59 (a solid invisible tile) would be placed at
[18,9] to prevent the moving platform from going back through the
quicksand.
Unfortunately, the way that this kludge was added is poor.
First, the conditional makes it so that it doesn't happen in ONLY
(11,7). Instead of being behind a positive conditional, the tile is
placed in the else-branch of an if-conditional that checks for the
normal case, i.e. if the current room is NOT (11,7), thus being a
negative conditional.
In other words, the positive conditional is "game.roomx == 111 &&
game.roomy == 107". To negate it, all you would have to do is
"!(game.roomx == 111 && game.roomy == 107)".
However, whoever wrote this decided to go one step further, and actually
DISTRIBUTE the negative into both statements. This would be fine, except
if they actually got it right. You see, according to De Morgan's laws,
when you distribute a negative across multiple statements you not only
have to negate the statements themselves, but you have to negate all the
CONJUNCTIONS, too. In other words, you have to change all "and"s into
"or"s and all "or"s into "and"s.
Instead of making the conditional "game.roomx != 111 || game.roomy !=
107", the person who wrote this forgot to replace the "and" with an
"or". Thus, it is "game.roomx != 111 && game.roomy != 107" instead. As a
result, if we re-negate this and take a look at the positive
conditional, i.e. the conditional that results in the else-branch
executing, it turns out to be "game.roomx == 111 || game.roomy == 107".
This ends up forming a cross-shape of rooms where this kludge happens.
As long as your room is either on the line x=11 or on the line y=7, this
kludge will execute.
You can see this if you go to Boldly To Go, since it is (11,13), which
is on the line x=11. Checkpoint in that room, then touch a disappearing
platform, wait for it to fully disappear, then die. Then an invisible
tile will be placed to the left of the spikes on the ceiling.
Anyway, to fix this, it's simple. Just change the "and" in the negative
conditional to an "or".
The second problem was that this kludge was happening in custom levels.
So I've added a map.custommode check to it. I made sure not to make the
same mistake originally made, i.e. I made sure to use an "or" instead of
an "and". Thus, when you re-negate the negative conditional and turn it
into the positive conditional, it reads: "game.roomx == 111 &&
game.roomy == 107 && !map.custommode".