Busy mode background images
Using 1.13 stable.
In Heretic, going from an intermission screen to a map produces a black screen during loading instead of a background. Entering an intermission from a map is fine.
While in Doom, the screen melt when going to an intermission screen from a map is pure white. Exiting a map from an intermission is fine.
Fixed|Heretic: Transition from intermission to next map
The busy mode transition frame was not being prepared at the
end of the Heretic intermission. Also, there was a waiting period
after the intermission where nothing was being drawn.