Skip rendering of OBJ_NONE objects to avoid a failed Assert (can happen when playing a demo then going to the editor)

CHANGELOG.txt

@@ -5,6 +5,7 @@ D2X-Rebirth Changelog
 main/game.c: Make sure Cursegp is initialised if using it to set an object when loading a game (EDITOR build). Thought I already committed this
 main/gameseq.c: Finish the game cleanly, closing Game_wind, if Current_level_num is 0
 editor/med.c: Reset the player object for the editor, since demo playback mucks it up
+main/render.c: Skip rendering of OBJ_NONE objects to avoid a failed Assert (can happen when playing a demo then going to the editor)
 
 20120416
 --------

main/render.c

@@ -1454,6 +1454,9 @@ void build_object_lists(int n_segs)
 				int new_segnum,list_pos;
 
 				obj = &Objects[objnum];
+				
+				if (obj->type == OBJ_NONE)
+					continue;
 
 				Assert( obj->segnum == segnum );