CallACS builtin is accessible from non-play scope

[argv]

As of GZDoom 3.5.0, the builtin function CallACS (and, presumably, the other ACS_* builtins) can be used from outside the play scope. This is obviously unsafe.

The attached pk3 demonstrates that unsafety, by spawning an imp from ui scope. To use:

1. Load it into GZDoom, along with a Doom-compatible IWAD.
2. Start a game.
3. Walk into an area where there's a decent amount of room above you.
4. Press the Use key.

That'll spawn an imp on top of you—from StaticEventHandler.UiTick!

[Graf Zahl]

Crap. And wanna bet that changing this will break several mods which use ACS to do some of their HUD work?