From b5c63e620ab34929ba854d80827cb4908fd52e0f Mon Sep 17 00:00:00 2001
From: Fabian Greffrath <fabian@greffrath.com>
Date: Tue, 16 Feb 2021 13:01:39 +0100
Subject: [PATCH] clean up some demo compatibility code

---
 Source/p_enemy.c | 12 +++++++-----
 Source/p_floor.c |  8 ++++----
 Source/p_setup.c |  2 +-
 3 files changed, 12 insertions(+), 10 deletions(-)

diff --git a/Source/p_enemy.c b/Source/p_enemy.c
index 7a82f909..c76c9080 100644
--- a/Source/p_enemy.c
+++ b/Source/p_enemy.c
@@ -409,17 +409,18 @@ static boolean P_Move(mobj_t *actor, boolean dropoff) // killough 9/12/98
         if (P_UseSpecialLine(actor, spechit[numspechit], 0))
 	  good |= spechit[numspechit] == blockline ? 1 : 2;
 
-      // [FG] cph - compatibility maze here
+      // [FG] compatibility maze here
       // Boom v2.01 and orig. Doom return "good"
       // Boom v2.02 and LxDoom return good && (P_Random(pr_trywalk)&3)
       // MBF plays even more games
 
-      if (!good || comp[comp_doorstuck])
+      if (demo_version < 202)
         return good;
       if (demo_version < 203)
-        return (P_Random(pr_trywalk)&3); /* jff 8/13/98 */
-      else /* finally, MBF code */
-        return ((P_Random(pr_opendoor) >= 230) ^ (good & 1));
+        return good && (compatibility || (P_Random(pr_trywalk)&3)); //jff 8/13/98
+      else
+      return good && (demo_version < 203 || comp[comp_doorstuck] ||
+		      (P_Random(pr_opendoor) >= 230) ^ (good & 1));
     }
   else
     actor->flags &= ~MF_INFLOAT;
@@ -2102,6 +2103,7 @@ void A_Detonate(mobj_t *mo)
 void A_Mushroom(mobj_t *actor)
 {
   int i, j, n = actor->info->damage;
+
   // Mushroom parameters are part of code pointer's state
   fixed_t misc1 = actor->state->misc1 ? actor->state->misc1 : FRACUNIT*4;
   fixed_t misc2 = actor->state->misc2 ? actor->state->misc2 : FRACUNIT/2;
diff --git a/Source/p_floor.c b/Source/p_floor.c
index 8edcdde5..89d23def 100644
--- a/Source/p_floor.c
+++ b/Source/p_floor.c
@@ -118,7 +118,7 @@ result_e T_MovePlane
           // Moving a floor up
           // jff 02/04/98 keep floor from moving thru ceilings
           // jff 2/22/98 weaken check to demo_compatibility
-          destheight = (demo_compatibility || comp[comp_floors] ||
+          destheight = (demo_compatibility || (demo_version >= 203 && comp[comp_floors]) ||
 			dest<sector->ceilingheight)? // killough 10/98
                           dest : sector->ceilingheight;
           if (sector->floorheight + speed > destheight)
@@ -141,7 +141,7 @@ result_e T_MovePlane
             flag = P_CheckSector(sector,crush); //jff 3/19/98 use faster chk
             if (flag == true)
             {
-              if (demo_compatibility || comp[comp_floors]) // killough 10/98
+              if (demo_compatibility || (demo_version >= 203 && comp[comp_floors])) // killough 10/98
                 if (crush == true) //jff 1/25/98 fix floor crusher
                   return crushed;
               sector->floorheight = lastpos;
@@ -821,7 +821,7 @@ int EV_BuildStairs
         if (tsec->floorpic != texture)
           continue;
 
-	if (demo_compatibility || demo_version >= 203)
+	if (demo_compatibility || demo_version >= 203 || compatibility)
 	{
 	height += stairsize;  // killough 10/98: intentionally left this way
 	}
@@ -830,7 +830,7 @@ int EV_BuildStairs
         if (P_SectorActive(floor_special,tsec)) //jff 2/22/98
 	  continue;
 
-	if (!demo_compatibility && demo_version < 203)
+	if (!demo_compatibility && demo_version < 203 && !compatibility)
 	{
 	height += stairsize;
 	}
diff --git a/Source/p_setup.c b/Source/p_setup.c
index 6b9808a7..5590f428 100644
--- a/Source/p_setup.c
+++ b/Source/p_setup.c
@@ -943,7 +943,7 @@ void P_RemoveSlimeTrails(void)                // killough 10/98
 		    v->r_y = (fixed_t)((dy2 * y0 + dx2 * y1 + dxy * (x0 - x1)) / s);
 
 		    // [FG] override actual vertex coordinates except in compatibility mode
-		    if (!demo_compatibility)
+		    if (demo_version >= 203)
 		    {
 		      v->x = v->r_x;
 		      v->y = v->r_y;