- Fixed: A_Respawn and P_NightmareRespawn() should not check for collision with world geometry.

The initial spawn did not, so this can prevent respawns of things that were initially
  spawned if they happen to intersect a wall.
- Fixed: Don't respawn actors inside the floor.
- Fixed: The final calls to P_FindFloorCeiling() in P_NightmareRespawn() and A_RestoreSpecialPosition
  also need to pass true as the second parameter. (Because this parameter is onlyspawnpos, not
  onlymidtex.)

SVN r3518 (trunk)

src/g_shared/a_pickups.cpp

@@ -384,8 +384,13 @@ DEFINE_ACTION_FUNCTION(AActor, A_RestoreSpecialPosition)
 			self->z += FloatBobOffsets[(self->FloatBobPhase + level.maptime) & 63];
 		}
 	}
-	// Redo floor/ceiling check, now with 3D floors
-	P_FindFloorCeiling(self);
+	// Redo floor/ceiling check, in case of 3D floors
+	P_FindFloorCeiling(self, true);
+	if (self->z < self->floorz)
+	{ // Do not reappear under the floor, even if that's where we were for the
+	  // initial spawn.
+		self->z = self->floorz;
+	}
 }
 
 int AInventory::StaticLastMessageTic;

src/p_local.h

@@ -405,8 +405,8 @@ extern TArray<line_t *> spechit;
 
 bool	P_TestMobjLocation (AActor *mobj);
 bool	P_TestMobjZ (AActor *mobj, bool quick=true, AActor **pOnmobj = NULL);
-bool	P_CheckPosition (AActor *thing, fixed_t x, fixed_t y, FCheckPosition &tm);
-bool	P_CheckPosition (AActor *thing, fixed_t x, fixed_t y);
+bool	P_CheckPosition (AActor *thing, fixed_t x, fixed_t y, FCheckPosition &tm, bool actorsonly=false);
+bool	P_CheckPosition (AActor *thing, fixed_t x, fixed_t y, bool actorsonly=false);
 AActor	*P_CheckOnmobj (AActor *thing);
 void	P_FakeZMovement (AActor *mo);
 bool	P_TryMove (AActor* thing, fixed_t x, fixed_t y, int dropoff, const secplane_t * onfloor, FCheckPosition &tm, bool missileCheck = false);
@@ -432,7 +432,7 @@ void	P_ResetSightCounters (bool full);
 bool	P_TalkFacing (AActor *player);
 void	P_UseLines (player_t* player);
 bool	P_UsePuzzleItem (AActor *actor, int itemType);
-void	P_FindFloorCeiling (AActor *actor, bool onlymidtex = false);
+void	P_FindFloorCeiling (AActor *actor, bool onlyspawnpos = false);
 
 bool	P_ChangeSector (sector_t* sector, int crunch, int amt, int floorOrCeil, bool isreset);
 

src/p_map.cpp

@@ -1256,7 +1256,7 @@ bool PIT_CheckThing (AActor *thing, FCheckPosition &tm)
 //
 //==========================================================================
 
-bool P_CheckPosition (AActor *thing, fixed_t x, fixed_t y, FCheckPosition &tm)
+bool P_CheckPosition (AActor *thing, fixed_t x, fixed_t y, FCheckPosition &tm, bool actorsonly)
 {
 	sector_t *newsec;
 	AActor *thingblocker;
@@ -1399,7 +1399,7 @@ bool P_CheckPosition (AActor *thing, fixed_t x, fixed_t y, FCheckPosition &tm)
 
 	thing->BlockingMobj = NULL;
 	thing->height = realheight;
-	if (thing->flags & MF_NOCLIP)
+	if (actorsonly || (thing->flags & MF_NOCLIP))
 		return (thing->BlockingMobj = thingblocker) == NULL;
 
 	FBlockLinesIterator it(box);
@@ -1435,10 +1435,10 @@ bool P_CheckPosition (AActor *thing, fixed_t x, fixed_t y, FCheckPosition &tm)
 	return (thing->BlockingMobj = thingblocker) == NULL;
 }
 
-bool P_CheckPosition (AActor *thing, fixed_t x, fixed_t y)
+bool P_CheckPosition (AActor *thing, fixed_t x, fixed_t y, bool actorsonly)
 {
 	FCheckPosition tm;
-	return P_CheckPosition(thing, x, y, tm);
+	return P_CheckPosition(thing, x, y, tm, actorsonly);
 }
 
 //----------------------------------------------------------------------------

src/p_mobj.cpp

@@ -2467,12 +2467,23 @@ void P_NightmareRespawn (AActor *mobj)
 	mo = AActor::StaticSpawn(RUNTIME_TYPE(mobj), x, y, z, NO_REPLACE, true);
 
 	if (z == ONFLOORZ)
+	{
 		mo->z += mobj->SpawnPoint[2];
+		if (mo->z < mo->floorz)
+		{ // Do not respawn monsters in the floor, even if that's where they
+		  // started. The initial P_ZMovement() call would have put them on
+		  // the floor right away, but we need them on the floor now so we
+		  // can use P_CheckPosition() properly.
+			mo->z = mo->floorz;
+		}
+	}
 	else if (z == ONCEILINGZ)
+	{
 		mo->z -= mobj->SpawnPoint[2];
+	}
 
 	// something is occupying its position?
-	if (!P_TestMobjLocation (mo))
+	if (!P_CheckPosition(mo, mo->x, mo->y, true))
 	{
 		//[GrafZahl] MF_COUNTKILL still needs to be checked here.
 		mo->ClearCounters();
@@ -2481,7 +2492,7 @@ void P_NightmareRespawn (AActor *mobj)
 	}
 
 	// If there are 3D floors, we need to find floor/ceiling again.
-	P_FindFloorCeiling(mo);
+	P_FindFloorCeiling(mo, true);
 
 	z = mo->z;
 

src/thingdef/thingdef_codeptr.cpp

@@ -2649,10 +2649,21 @@ DEFINE_ACTION_FUNCTION_PARAMS(AActor, A_Respawn)
 	{
 		// [KS] DIE DIE DIE DIE erm *ahem* =)
 		oktorespawn = P_TeleportMove(self, self->x, self->y, self->z, true);
+		if (oktorespawn)
+		{ // Need to do this over again, since P_TeleportMove() will redo
+		  // it with the proper point-on-side calculation.
+			self->UnlinkFromWorld();
+			self->LinkToWorld(true);
+			sector_t *sec = self->Sector;
+			self->dropoffz =
+			self->floorz = sec->floorplane.ZatPoint(self->x, self->y);
+			self->ceilingz = sec->ceilingplane.ZatPoint(self->x, self->y);
+			P_FindFloorCeiling(self, true);
+		}
 	}
 	else
 	{
-		oktorespawn = P_TestMobjLocation(self);
+		oktorespawn = P_CheckPosition(self, self->x, self->z, true);
 	}
 
 	if (oktorespawn)