- set proper game state after ending the level summary screen.

Fixes #20.

source/core/screenjob.cpp

@@ -452,6 +452,10 @@ void RunScreenJobFrame()
 	// we cannot recover from this because we have no completion callback to call.
 	if (!runner) I_Error("Trying to run a non-existent screen job");
 	auto res = runner->RunFrame();
-	if (!res) DeleteScreenJob();
+	if (!res)
+	{
+		assert(gamestate != GS_INTERMISSION && gamestate != GS_INTRO);
+		DeleteScreenJob();
+	}
 }
 

source/games/duke/src/premap.cpp

@@ -1132,7 +1132,7 @@ void exitlevel(void)
 
                 // Clear potentially loaded per-map ART only after the bonus screens.
                 artClearMapArt();
-
+                gamestate = GS_LEVEL;
                 if (endofgame)
                 {
                     ud.eog = 0;