Confirmed Scripting a game end during title demos breaks menus

[fickleheart]

Method:

• Add a script such as the following:
  addHook("ThinkFrame", do
      if leveltime > 3*TICRATE then
          G_ExitLevel(1100, true)
      end
  end)
• Wait on the title screen until a demo plays and is abruptly finished

Expected behavior:
The game should continue to operate as normal

Actual behavior:
Upon opening the title menu, no keys have any effect. The console key can be used to open the console, which is immediately closed.

Skipping or not skipping the intermission screen doesn't change the behavior. If the G_ExitLevel call sends the player to another map instead, they'll go to that map with zero lives (in a game over state) and the player will have full interactive control.

This was discovered while testing one of MPC's submissions