When I had a trapdoor in open position above a ladder, I was able to climb up the ladder and continue climbing on top of the trapdoor.
*What I expected to happen was to be stuck on the trapdoor *
What ended up happening was that I did not stop, but I continued to climb up the trapdoor
Steps to Reproduce:
1. Place any number of ladders in a straight line up
2. Place a trapdoor above the highest ladder
3. Place some more ladders above the trapdoor
Actually this is the fix for a bug i reported years ago. Trap Doors were never intended to obstruct a ladder and the old behavior was the result of a bug introduced by the fix that stopped gap ladders. Trap doors are now Finally Behaving properly why are you reporting the fix for a major annoyance as a bug ?
Also trap doors have a higher material cost than ladders so there is no point using them as ladders like you showed in your screenshot
It kinda shocks me that this was only now being fixed