[1.20] While loop pattern: infinite loop with an empty loop body freezes the server

[yezhiyi9670]

Mod version: 5.0.2-forge

To reproduce:

1. Add a True onto the stack.
2. Add an empty list onto the stack.
3. Draw the while loop pattern. ❎ Observe that the server will be frozen. It will not respond to anything such as chats.

More info: Hex casting on 1.20 limits how many actions a hex can do, not the total number of meta-evaluations a hex can perform. An infinite while loop with an empty loop body does no action so it will never exceed the action limit.

Suggested fix: Use up one extra allowed action for each iteration, or explicitly forbidding starting an empty while loop when the iota below that empty pattern list is a truthy.

[walksanatora]

I think banning empty execution would be better. thatway no time is wasted trying to spin through the 1m itterations