Collapsing floor key holder can block level connectivity

[brturn]

CE 1.14.1 seed 20250812

The collapsing floor machine is generated first and the level is fully connected when it starts. The tiles placed for the machine are FLOOR_FLOODABLE, which are non-blocking.

Then it generates the lava area machine just to the south west. The lava tiles are blocking, but the connectivity test passes because the FLOOR_FLOODABLE tiles are non-blocking.

Adding T_OBSTRUCTS_PASSABILITY to the FLOOR_FLOODABLE tile causes the machine to fail at that location (though not due to connectivity).

Since the FLOOR_FLOODABLE tile is shared with the eel water trap, a fix might be to use a different tile for the collapsing floor (may need a new one) which does have the T_OBSTRUCTS_PASSABILITY flag.

Reported by azrealiraizaI on Discord (also by hal7767 earlier).

https://discord.com/channels/205277826788622337/205347357745872896/1437942175194288279 https://discord.com/channels/622393898064543759/647802299783184384/1438022125607976990