- fixed many compilation errors with GCC and Clang

# Conflicts:
#	src/dobjgc.h

src/actorptrselect.cpp

@@ -151,7 +151,7 @@ void VerifyTargetChain(AActor *self, bool preciseMissileCheck)
 			{
 				// if any of the actors from self to (inclusive) origin match the next actor,
 				// self has reached/created a loop
-				self->target = NULL;
+				self->target = nullptr;
 				return;
 			}
 			if (compare == origin) break; // when "compare" = origin, we know that the next actor is, and should be "next"
@@ -177,7 +177,7 @@ void VerifyMasterChain(AActor *self)
 		{
 			if (compare == next)
 			{
-				self->master = NULL;
+				self->master = nullptr;
 				return;
 			}
 			if (compare == origin) break;
@@ -216,4 +216,4 @@ void ASSIGN_AAPTR(AActor *toActor, int toSlot, AActor *ptr, int flags)
 			toActor->tracer = ptr; 
 			break;
 	}
-}
+}

src/b_func.cpp

@@ -357,7 +357,7 @@ AActor *DBot::Choose_Mate ()
 	if (mate)
 	{
 		if (mate->health <= 0)
-			mate = NULL;
+			mate = nullptr;
 		else
 			last_mate = mate;
 	}
@@ -367,7 +367,7 @@ AActor *DBot::Choose_Mate ()
 	//Check old_mates status.
 	if (last_mate)
 		if (last_mate->health <= 0)
-			last_mate = NULL;
+			last_mate = nullptr;
 
 	target = NULL;
 	closest_dist = FLT_MAX;

src/b_game.cpp

@@ -178,12 +178,12 @@ void FCajunMaster::Main ()
 void FCajunMaster::Init ()
 {
 	botnum = 0;
-	firstthing = NULL;
+	firstthing = nullptr;
 	spawn_tries = 0;
 	freeze = false;
 	observer = false;
-	body1 = NULL;
-	body2 = NULL;
+	body1 = nullptr;
+	body2 = nullptr;
 
 	if (ctf && teamplay == false)
 		teamplay = true; //Need teamplay for ctf. (which is not done yet)

src/b_think.cpp

@@ -126,7 +126,7 @@ void DBot::ThinkForMove (ticcmd_t *cmd)
 		(!missile->Vel.X || !missile->Vel.Y || !Check_LOS(missile, SHOOTFOV*3/2)))
 	{
 		sleft = !sleft;
-		missile = NULL; //Probably ended its travel.
+		missile = nullptr; //Probably ended its travel.
 	}
 
 #if 0	// this has always been broken and without any reference it cannot be fixed.
@@ -188,7 +188,7 @@ void DBot::ThinkForMove (ticcmd_t *cmd)
 			}
 		}
 
-		dest = NULL; //To let bot turn right
+		dest = nullptr; //To let bot turn right
 
 		if (GetBotInfo(player->ReadyWeapon).MoveCombatDist == 0)
 			player->mo->flags &= ~MF_DROPOFF; //Don't jump off any ledges when fighting.
@@ -242,7 +242,7 @@ void DBot::ThinkForMove (ticcmd_t *cmd)
 		{
 			if (mate == dest && pr_botmove.Random() < 32)
 			{ // [RH] If the mate is the dest, pick a new dest sometimes
-				dest = NULL;
+				dest = nullptr;
 			}
 			goto roam;
 		}
@@ -269,7 +269,7 @@ void DBot::ThinkForMove (ticcmd_t *cmd)
 
 		if (dest && !(dest->flags&MF_SPECIAL) && dest->health < 0)
 		{ //Roaming after something dead.
-			dest = NULL;
+			dest = nullptr;
 		}
 
 		if (dest == NULL)
@@ -338,7 +338,7 @@ void DBot::ThinkForMove (ticcmd_t *cmd)
 	if (!t_roam && dest)
 	{
 		prev = dest;
-		dest = NULL;
+		dest = nullptr;
 	}
 
 	if (t_fight<(AFTERTICS/2))
@@ -443,5 +443,5 @@ void DBot::Set_enemy ()
 	}
 	//Verify that that enemy is really something alive that bot can kill.
 	if (enemy && ((enemy->health < 0 || !(enemy->flags&MF_SHOOTABLE)) || player->mo->IsFriend(enemy)))
-		enemy = NULL;
+		enemy = nullptr;
 }

src/fragglescript/t_func.cpp

@@ -3322,7 +3322,7 @@ void FParser::SF_Resurrect()
 		mo->Height = mo->GetDefault()->Height;
 		mo->radius = mo->GetDefault()->radius;
 		mo->Revive();
-		mo->target = NULL;
+		mo->target = nullptr;
 	}
 }
 

src/fragglescript/t_prepro.cpp

@@ -130,7 +130,7 @@ void DFsScript::ClearSections()
 			var->Destroy();
 			var = next;
 		}
-		sections[i] = NULL;
+		sections[i] = nullptr;
 	}
 }
 

src/fragglescript/t_variable.cpp

@@ -178,9 +178,9 @@ DFsVariable::DFsVariable(const char * _name)
 {
 	Name=_name;
 	type=svt_int;
-	actor = NULL;
+	actor = nullptr;
 	value.i=0;
-	next=NULL;
+	next = nullptr;
 }
 
 //==========================================================================

src/g_game.cpp

@@ -1721,7 +1721,7 @@ void G_DoPlayerPop(int playernum)
 			players[playernum].mo->Destroy();
 		}
 		players[playernum].mo = NULL;
-		players[playernum].camera = NULL;
+		players[playernum].camera = nullptr;
 	}
 
 	players[playernum].DestroyPSprites();
@@ -2785,7 +2785,7 @@ bool G_CheckDemoStatus (void)
 		for (int i = 1; i < MAXPLAYERS; i++)
 			playeringame[i] = 0;
 		consoleplayer = 0;
-		players[0].camera = NULL;
+		players[0].camera = nullptr;
 		if (StatusBar != NULL)
 		{
 			StatusBar->AttachToPlayer (&players[0]);

src/g_level.cpp

@@ -1277,7 +1277,7 @@ void G_StartTravel ()
 		{
 			AActor *pawn = players[i].mo;
 			AActor *inv;
-			players[i].camera = NULL;
+			players[i].camera = nullptr;
 
 			// Only living players travel. Dead ones get a new body on the new level.
 			if (players[i].health > 0)
@@ -1379,8 +1379,8 @@ int G_FinishTravel ()
 		{
 			P_FindFloorCeiling(pawn);
 		}
-		pawn->target = NULL;
-		pawn->lastenemy = NULL;
+		pawn->target = nullptr;
+		pawn->lastenemy = nullptr;
 		pawn->player->mo = pawn;
 		pawn->player->camera = pawn;
 		pawn->player->viewheight = pawn->player->DefaultViewHeight();

src/g_statusbar/shared_sbar.cpp

@@ -451,7 +451,7 @@ void DBaseStatusBar::OnDestroy ()
 			msg->Destroy();
 			msg = next;
 		}
-		Messages[i] = NULL;
+		Messages[i] = nullptr;
 	}
 	if (AltHud) AltHud->Destroy();
 	Super::OnDestroy();
@@ -723,7 +723,7 @@ DHUDMessageBase *DBaseStatusBar::DetachMessage (DHUDMessageBase *msg)
 		if (probe != NULL)
 		{
 			*prev = probe->Next;
-			probe->Next = NULL;
+			probe->Next = nullptr;
 			return probe;
 		}
 	}
@@ -745,7 +745,7 @@ DHUDMessageBase *DBaseStatusBar::DetachMessage (uint32_t id)
 		if (probe != NULL)
 		{
 			*prev = probe->Next;
-			probe->Next = NULL;
+			probe->Next = nullptr;
 			return probe;
 		}
 	}
@@ -764,7 +764,7 @@ void DBaseStatusBar::DetachAllMessages ()
 	{
 		DHUDMessageBase *probe = Messages[i];
 
-		Messages[i] = NULL;
+		Messages[i] = nullptr;
 		while (probe != NULL)
 		{
 			DHUDMessageBase *next = probe->Next;

src/intermission/intermission.cpp

@@ -729,7 +729,7 @@ DIntermissionController::DIntermissionController(FIntermissionDescriptor *Desc,
 	mIndex = 0;
 	mAdvance = false;
 	mSentAdvance = false;
-	mScreen = NULL;
+	mScreen = nullptr;
 	mFirst = true;
 	mGameState = state;
 }

src/p_acs.cpp

@@ -4023,15 +4023,15 @@ int DoSetMaster (AActor *self, AActor *master)
                 self->flags = (self->flags & ~MF_FRIENDLY) | (master->flags & MF_FRIENDLY);
                 level.total_monsters += self->CountsAsKill();
                 // Don't attack your new master
-                if (self->target == self->master) self->target = NULL;
-                if (self->lastenemy == self->master) self->lastenemy = NULL;
-                if (self->LastHeard == self->master) self->LastHeard = NULL;
+                if (self->target == self->master) self->target = nullptr;
+                if (self->lastenemy == self->master) self->lastenemy = nullptr;
+                if (self->LastHeard == self->master) self->LastHeard = nullptr;
                 return 1;
             }
             else if (master->player)
             {
                 // [KS] Be friendly to this player
-                self->master = NULL;
+                self->master = nullptr;
                 level.total_monsters -= self->CountsAsKill();
                 self->flags|=MF_FRIENDLY;
                 self->SetFriendPlayer(master->player);
@@ -4046,15 +4046,15 @@ int DoSetMaster (AActor *self, AActor *master)
                     }
                 }
                 // And stop attacking him if necessary.
-                if (self->target == master) self->target = NULL;
-                if (self->lastenemy == master) self->lastenemy = NULL;
-                if (self->LastHeard == master) self->LastHeard = NULL;
+                if (self->target == master) self->target = nullptr;
+                if (self->lastenemy == master) self->lastenemy = nullptr;
+                if (self->LastHeard == master) self->LastHeard = nullptr;
                 return 1;
             }
         }
         else
         {
-            self->master = NULL;
+            self->master = nullptr;
             self->FriendPlayer = 0;
             // Go back to whatever friendliness we usually have...
             defs = self->GetDefault();
@@ -4062,9 +4062,9 @@ int DoSetMaster (AActor *self, AActor *master)
             self->flags = (self->flags & ~MF_FRIENDLY) | (defs->flags & MF_FRIENDLY);
             level.total_monsters += self->CountsAsKill();
             // ...And re-side with our friends.
-            if (self->target && !self->IsHostile (self->target)) self->target = NULL;
-            if (self->lastenemy && !self->IsHostile (self->lastenemy)) self->lastenemy = NULL;
-            if (self->LastHeard && !self->IsHostile (self->LastHeard)) self->LastHeard = NULL;
+            if (self->target && !self->IsHostile (self->target)) self->target = nullptr;
+            if (self->lastenemy && !self->IsHostile (self->lastenemy)) self->lastenemy = nullptr;
+            if (self->LastHeard && !self->IsHostile (self->LastHeard)) self->LastHeard = nullptr;
             return 1;
         }
     }

src/p_actionfunctions.cpp

@@ -585,7 +585,7 @@ DEFINE_ACTION_FUNCTION(AActor, A_RearrangePointers)
 		if (!(PTROP_UNSAFETARGET & flags)) VerifyTargetChain(self);
 		break;
 	case AAPTR_NULL:
-		self->target = NULL;
+		self->target = nullptr;
 		// THIS IS NOT "A_ClearTarget", so no other targeting info is removed
 		break;
 	}
@@ -602,7 +602,7 @@ DEFINE_ACTION_FUNCTION(AActor, A_RearrangePointers)
 		if (!(PTROP_UNSAFEMASTER & flags)) VerifyMasterChain(self);
 		break;
 	case AAPTR_NULL:
-		self->master = NULL;
+		self->master = nullptr;
 		break;
 	}
 
@@ -615,7 +615,7 @@ DEFINE_ACTION_FUNCTION(AActor, A_RearrangePointers)
 		self->tracer = getmaster;
 		break; // no verification deemed necessary; the engine never follows a tracer chain(?)
 	case AAPTR_NULL:
-		self->tracer = NULL;
+		self->tracer = nullptr;
 		break;
 	}
 	return 0;
@@ -786,7 +786,7 @@ DEFINE_ACTION_FUNCTION(AActor, A_SeekerMissile)
 	{
 		if (flags & SMF_LOOK)
 		{ // This monster is no longer seekable, so let us look for another one next time.
-			self->tracer = NULL;
+			self->tracer = nullptr;
 		}
 	}
 	return 0;
@@ -1996,17 +1996,17 @@ DEFINE_ACTION_FUNCTION(AActor, A_Respawn)
 		//      ...Actually it's better off an option, so you have better control over monster behavior.
 		if (!(flags & RSF_KEEPTARGET))
 		{
-			self->target = NULL;
-			self->LastHeard = NULL;
-			self->lastenemy = NULL;
+			self->target = nullptr;
+			self->LastHeard = nullptr;
+			self->lastenemy = nullptr;
 		}
 		else
 		{
 			// Don't attack yourself (Re: "Marine targets itself after suicide")
 			if (self->target == self)
-				self->target = NULL;
+				self->target = nullptr;
 			if (self->lastenemy == self)
-				self->lastenemy = NULL;
+				self->lastenemy = nullptr;
 		}
 
 		self->flags  = (defs->flags & ~MF_FRIENDLY) | (self->flags & MF_FRIENDLY);

src/p_conversation.cpp

@@ -1081,8 +1081,8 @@ static void HandleReply(player_t *player, bool isconsole, int nodenum, int reply
 	{
 		npc->flags5 &= ~MF5_INCONVERSATION;
 		player->ConversationFaceTalker = false;
-		player->ConversationNPC = NULL;
-		player->ConversationPC = NULL;
+		player->ConversationNPC = nullptr;
+		player->ConversationPC = nullptr;
 		player->ConversationNPCAngle = 0.;
 	}
 
@@ -1128,8 +1128,8 @@ void P_ConversationCommand (int netcode, int pnum, uint8_t **stream)
 		if (netcode == DEM_CONVNULL)
 		{
 			player->ConversationFaceTalker = false;
-			player->ConversationNPC = NULL;
-			player->ConversationPC = NULL;
+			player->ConversationNPC = nullptr;
+			player->ConversationPC = nullptr;
 			player->ConversationNPCAngle = 0.;
 		}
 	}

src/p_doors.cpp

@@ -151,7 +151,7 @@ void DDoor::Tick ()
 			{
 			case doorRaise:
 			case doorClose:
-				m_Sector->ceilingdata = NULL;	//jff 2/22/98
+				m_Sector->ceilingdata = nullptr;	//jff 2/22/98
 				Destroy ();						// unlink and free
 				break;
 				
@@ -202,7 +202,7 @@ void DDoor::Tick ()
 				
 			case doorCloseWaitOpen:
 			case doorOpen:
-				m_Sector->ceilingdata = NULL;	//jff 2/22/98
+				m_Sector->ceilingdata = nullptr;	//jff 2/22/98
 				Destroy ();						// unlink and free
 				break;
 				
@@ -597,7 +597,7 @@ void DAnimatedDoor::Tick ()
 	switch (m_Status)
 	{
 	case Dead:
-		m_Sector->ceilingdata = NULL;
+		m_Sector->ceilingdata = nullptr;
 		Destroy ();
 		break;
 
@@ -612,7 +612,7 @@ void DAnimatedDoor::Tick ()
 
 				if (m_Delay == 0)
 				{
-					m_Sector->ceilingdata = NULL;
+					m_Sector->ceilingdata = nullptr;
 					Destroy ();
 					break;
 				}
@@ -651,7 +651,7 @@ void DAnimatedDoor::Tick ()
 			{
 				// IF DOOR IS DONE CLOSING...
 				m_Sector->MoveCeiling (2048., m_BotDist, -1);
-				m_Sector->ceilingdata = NULL;
+				m_Sector->ceilingdata = nullptr;
 				Destroy ();
 				// Unset blocking flags on lines that didn't start with them. Since the
 				// ceiling is down now, we shouldn't need this flag anymore to keep things

src/p_enemy.cpp

@@ -1346,7 +1346,7 @@ int P_LookForTID (AActor *actor, INTBOOL allaround, FLookExParams *params)
 	if (actor->LastLookActor != NULL &&
 		actor->LastLookActor->tid != actor->TIDtoHate)
 	{
-		actor->LastLookActor = NULL;
+		actor->LastLookActor = nullptr;
 	}
 
 	FActorIterator iterator (actor->TIDtoHate, actor->LastLookActor);
@@ -1411,12 +1411,12 @@ int P_LookForTID (AActor *actor, INTBOOL allaround, FLookExParams *params)
 			if (!actor->IsFriend(actor->lastenemy))
 			{
 				actor->target = actor->lastenemy;
-				actor->lastenemy = NULL;
+				actor->lastenemy = nullptr;
 				return true;
 			}
 			else
 			{
-				actor->lastenemy = NULL;
+				actor->lastenemy = nullptr;
 			}
 		}
 	}
@@ -1550,12 +1550,12 @@ int P_LookForEnemies (AActor *actor, INTBOOL allaround, FLookExParams *params)
 			if (!actor->IsFriend(actor->lastenemy))
 			{
 				actor->target = actor->lastenemy;
-				actor->lastenemy = NULL;
+				actor->lastenemy = nullptr;
 				return true;
 			}
 			else
 			{
-				actor->lastenemy = NULL;
+				actor->lastenemy = nullptr;
 			}
 		}
 	}
@@ -1684,12 +1684,12 @@ int P_LookForPlayers (AActor *actor, INTBOOL allaround, FLookExParams *params)
 					if (!actor->IsFriend(actor->lastenemy))
 					{
 						actor->target = actor->lastenemy;
-						actor->lastenemy = NULL;
+						actor->lastenemy = nullptr;
 						return true;
 					}
 					else
 					{
-						actor->lastenemy = NULL;
+						actor->lastenemy = nullptr;
 					}
 				}
 			}
@@ -1849,7 +1849,7 @@ DEFINE_ACTION_FUNCTION(AActor, A_Look)
 	if (self->target == self->goal)
 	{
 		if (self->reactiontime > level.maptime)
-			self->target = NULL;
+			self->target = nullptr;
 	}
 	else if (self->SeeSound)
 	{
@@ -1936,7 +1936,7 @@ DEFINE_ACTION_FUNCTION(AActor, A_LookEx)
 					if (maxheardist && dist > maxheardist)
 					{
 						targ = NULL;
-						self->LastHeard = NULL;
+						self->LastHeard = nullptr;
 					}
 				}
 			}
@@ -1995,7 +1995,7 @@ DEFINE_ACTION_FUNCTION(AActor, A_LookEx)
             
             // [KS] The target can become ourselves in rare circumstances (like
             // if we committed suicide), so if that's the case, just ignore it.
-            if (self->target == self) self->target = NULL;
+            if (self->target == self) self->target = nullptr;
 
 			if (self->target != NULL)
 			{
@@ -2031,7 +2031,7 @@ DEFINE_ACTION_FUNCTION(AActor, A_LookEx)
 	if (self->target == self->goal)
 	{
 		if (self->reactiontime > level.maptime)
-			self->target = NULL;
+			self->target = nullptr;
 	}
 	else if (self->SeeSound && !(flags & LOF_NOSEESOUND))
 	{
@@ -2073,7 +2073,7 @@ DEFINE_ACTION_FUNCTION(AActor, A_LookEx)
 DEFINE_ACTION_FUNCTION(AActor, A_ClearLastHeard)
 {
 	PARAM_SELF_PROLOGUE(AActor);
-	self->LastHeard = NULL;
+	self->LastHeard = nullptr;
 	return 0;
 }
 
@@ -2235,7 +2235,7 @@ void A_DoChase (AActor *actor, bool fastchase, FState *meleestate, FState *missi
 		actor->target->renderflags & RF_INVISIBLE &&
 		actor->target != actor->goal)
 	{
-		actor->target = NULL;
+		actor->target = nullptr;
 	}
 
 	// modify target threshold
@@ -2284,7 +2284,7 @@ void A_DoChase (AActor *actor, bool fastchase, FState *meleestate, FState *missi
 
 	// [RH] If the target is dead or a friend (and not a goal), stop chasing it.
 	if (actor->target && actor->target != actor->goal && (actor->target->health <= 0 || actor->IsFriend(actor->target)))
-		actor->target = NULL;
+		actor->target = nullptr;
 
 	// [RH] Friendly monsters will consider chasing whoever hurts a player if they
 	// don't already have a target.
@@ -2408,7 +2408,7 @@ void A_DoChase (AActor *actor, bool fastchase, FState *meleestate, FState *missi
 				actor->reactiontime = actor->GetDefault()->reactiontime;
 				actor->Angles.Yaw = lastgoalang;		// Look in direction of last goal
 			}
-			if (actor->target == actor->goal) actor->target = NULL;
+			if (actor->target == actor->goal) actor->target = nullptr;
 			actor->flags |= MF_JUSTATTACKED;
 			if (newgoal != NULL && delay != 0)
 			{
@@ -2702,8 +2702,8 @@ bool P_CheckForResurrection(AActor *self, bool usevilestates)
 				{
 					// If this is a friendly Arch-Vile (which is turning the resurrected monster into its friend)
 					// and the Arch-Vile is currently targetting the resurrected monster the target must be cleared.
-					if (self->lastenemy == temp) self->lastenemy = NULL;
-					if (self->lastenemy == corpsehit) self->lastenemy = NULL;
+					if (self->lastenemy == temp) self->lastenemy = nullptr;
+					if (self->lastenemy == corpsehit) self->lastenemy = nullptr;
 					if (temp == self->target) temp = NULL;
 				}
 				self->target = temp;

src/p_floor.cpp

@@ -181,7 +181,7 @@ void DFloor::Tick ()
 				}
 			}
 
-			m_Sector->floordata = NULL; //jff 2/22/98
+			m_Sector->floordata = nullptr; //jff 2/22/98
 			StopInterpolation();
 
 			//jff 2/26/98 implement stair retrigger lockout while still building
@@ -561,7 +561,7 @@ bool EV_FloorCrushStop (int tag, line_t *line)
 		{
 			SN_StopSequence (sec, CHAN_FLOOR);
 			sec->floordata->Destroy ();
-			sec->floordata = NULL;
+			sec->floordata = nullptr;
 		}
 	}
 	return true;
@@ -900,12 +900,12 @@ void DElevator::OnDestroy()
 	if (m_Interp_Ceiling != NULL)
 	{
 		m_Interp_Ceiling->DelRef();
-		m_Interp_Ceiling = NULL;
+		m_Interp_Ceiling = nullptr;
 	}
 	if (m_Interp_Floor != NULL)
 	{
 		m_Interp_Floor->DelRef();
-		m_Interp_Floor = NULL;
+		m_Interp_Floor = nullptr;
 	}
 	Super::OnDestroy();
 }
@@ -964,8 +964,8 @@ void DElevator::Tick ()
 		// make floor stop sound
 		SN_StopSequence (m_Sector, CHAN_FLOOR);
 
-		m_Sector->floordata = NULL;		//jff 2/22/98
-		m_Sector->ceilingdata = NULL;	//jff 2/22/98
+		m_Sector->floordata = nullptr;		//jff 2/22/98
+		m_Sector->ceilingdata = nullptr;	//jff 2/22/98
 		Destroy ();		// remove elevator from actives
 	}
 }
@@ -1225,11 +1225,11 @@ void DWaggleBase::DoWaggle (bool ceiling)
 			P_ChangeSector (m_Sector, true, dist, ceiling, false);
 			if (ceiling)
 			{
-				m_Sector->ceilingdata = NULL;
+				m_Sector->ceilingdata = nullptr;
 			}
 			else
 			{
-				m_Sector->floordata = NULL;
+				m_Sector->floordata = nullptr;
 			}
 			Destroy ();
 			return;

src/p_interaction.cpp

@@ -585,8 +585,8 @@ void AActor::Die (AActor *source, AActor *inflictor, int dmgflags, FName MeansOf
 				if (players[i].Bot != NULL && this == players[i].Bot->enemy)
 				{
 					if (players[i].Bot->dest ==  players[i].Bot->enemy)
-						players[i].Bot->dest = NULL;
-					players[i].Bot->enemy = NULL;
+						players[i].Bot->dest = nullptr;
+					players[i].Bot->enemy = nullptr;
 				}
 			}
 

src/p_lnspec.cpp

@@ -1627,7 +1627,7 @@ FUNC(LS_Thing_Hate)
 			if (arg2 != 0)
 			{
 				hater->TIDtoHate = arg1;
-				hater->LastLookActor = NULL;
+				hater->LastLookActor = nullptr;
 
 				// If the TID to hate is 0, then don't forget the target and
 				// lastenemy fields.
@@ -1635,11 +1635,11 @@ FUNC(LS_Thing_Hate)
 				{
 					if (hater->target != NULL && hater->target->tid != arg1)
 					{
-						hater->target = NULL;
+						hater->target = nullptr;
 					}
 					if (hater->lastenemy != NULL && hater->lastenemy->tid != arg1)
 					{
-						hater->lastenemy = NULL;
+						hater->lastenemy = nullptr;
 					}
 				}
 			}
@@ -1833,7 +1833,7 @@ FUNC(LS_Thing_SetGoal)
 			{ // Targeting a goal already? -> don't target it anymore.
 			  // A_Look will set it to the goal, presuming no real targets
 			  // come into view by then.
-				self->target = NULL;
+				self->target = nullptr;
 			}
 			self->goal = goal;
 			if (arg3 == 0)

src/p_map.cpp

@@ -2345,7 +2345,7 @@ bool P_TryMove(AActor *thing, const DVector2 &pos,
 				&& bglobal.IsDangerous(tm.sector))
 			{
 				thing->player->Bot->prev = thing->player->Bot->dest;
-				thing->player->Bot->dest = NULL;
+				thing->player->Bot->dest = nullptr;
 				thing->Vel.X = thing->Vel.Y = 0;
 				thing->SetZ(oldz);
 				thing->flags6 &= ~MF6_INTRYMOVE;

src/p_mobj.cpp

@@ -1727,7 +1727,7 @@ bool P_SeekerMissile (AActor *actor, double thresh, double turnMax, bool precise
 	}
 	if (!(target->flags & MF_SHOOTABLE))
 	{ // Target died
-		actor->tracer = NULL;
+		actor->tracer = nullptr;
 		return false;
 	}
 	if (speed == 0)
@@ -5071,14 +5071,14 @@ AActor *P_SpawnPlayer (FPlayerStart *mthing, int playernum, int flags)
 	p->fixedlightlevel = -1;
 	p->viewheight = p->DefaultViewHeight();
 	p->inconsistant = 0;
-	p->attacker = NULL;
+	p->attacker = nullptr;
 	p->spreecount = 0;
 	p->multicount = 0;
 	p->lastkilltime = 0;
 	p->BlendR = p->BlendG = p->BlendB = p->BlendA = 0.f;
 	p->Uncrouch();
 	p->MinPitch = p->MaxPitch = 0.;	// will be filled in by PostBeginPlay()/netcode
-	p->MUSINFOactor = NULL;
+	p->MUSINFOactor = nullptr;
 	p->MUSINFOtics = -1;
 	p->Vel.Zero();	// killough 10/98: initialize bobbing to 0.
 
@@ -5174,7 +5174,7 @@ AActor *P_SpawnPlayer (FPlayerStart *mthing, int playernum, int flags)
 			TThinkerIterator<AActor> it;
 			while ((th = it.Next()))
 			{
-				if (th->LastHeard == oldactor) th->LastHeard = NULL;
+				if (th->LastHeard == oldactor) th->LastHeard = nullptr;
 			}
 			for(auto &sec : level.sectors)
 			{
@@ -7141,8 +7141,8 @@ void AActor::Revive()
 	if (SpawnFlags & MTF_FRIENDLY) flags |= MF_FRIENDLY;
 	DamageType = info->DamageType;
 	health = SpawnHealth();
-	target = NULL;
-	lastenemy = NULL;
+	target = nullptr;
+	lastenemy = nullptr;
 
 	// [RH] If it's a monster, it gets to count as another kill
 	if (CountsAsKill())

src/p_spec.cpp

@@ -996,7 +996,7 @@ void P_SetupPortals()
 		if (s.mType == PORTS_STACKEDSECTORTHING && s.mSkybox)
 		{
 			s.mDisplacement = s.mSkybox->Pos() - s.mSkybox->target->Pos();
-			s.mSkybox = NULL;
+			s.mSkybox = nullptr;
 		}
 	}
 }

src/r_data/r_interpolate.cpp

@@ -223,7 +223,7 @@ void FInterpolator::AddInterpolation(DInterpolation *interp)
 {
 	interp->Next = Head;
 	if (Head != NULL) Head->Prev = interp;
-	interp->Prev = NULL;
+	interp->Prev = nullptr;
 	Head = interp;
 	count++;
 }
@@ -239,15 +239,15 @@ void FInterpolator::RemoveInterpolation(DInterpolation *interp)
 	if (Head == interp)
 	{
 		Head = interp->Next;
-		if (Head != NULL) Head->Prev = NULL;
+		if (Head != nullptr) Head->Prev = nullptr;
 	}
 	else
 	{
 		if (interp->Prev != NULL) interp->Prev->Next = interp->Next;
 		if (interp->Next != NULL) interp->Next->Prev = interp->Prev;
 	}
-		interp->Next = NULL;
-		interp->Prev = NULL;
+		interp->Next = nullptr;
+		interp->Prev = nullptr;
 		count--;
 }
 
@@ -303,11 +303,11 @@ void FInterpolator::RestoreInterpolations()
 void FInterpolator::ClearInterpolations()
 {
 	DInterpolation *probe = Head;
-	Head = NULL;
-	while (probe != NULL)
+	Head = nullptr;
+	while (probe != nullptr)
 	{
 		DInterpolation *next = probe->Next;
-		probe->Next = probe->Prev = NULL;
+		probe->Next = probe->Prev = nullptr;
 		probe->Destroy();
 		probe = next;
 	}
@@ -328,8 +328,8 @@ void FInterpolator::ClearInterpolations()
 
 DInterpolation::DInterpolation()
 {
-	Next = NULL;
-	Prev = NULL;
+	Next = nullptr;
+	Prev = nullptr;
 	refcount = 0;
 }
 

src/s_sndseq.cpp

@@ -309,7 +309,7 @@ IMPLEMENT_POINTERS_END
 DSeqNode::DSeqNode ()
 : m_SequenceChoices(0)
 {
-	m_Next = m_Prev = m_ChildSeqNode = m_ParentSeqNode = NULL;
+	m_Next = m_Prev = m_ChildSeqNode = m_ParentSeqNode = nullptr;
 }
 
 void DSeqNode::Serialize(FSerializer &arc)
@@ -397,8 +397,8 @@ void DSeqNode::OnDestroy()
 	if (m_ParentSeqNode != NULL && m_ParentSeqNode->m_ChildSeqNode == this)
 	{
 		m_ParentSeqNode->m_SequencePtr++;
-		m_ParentSeqNode->m_ChildSeqNode = NULL;
-		m_ParentSeqNode = NULL;
+		m_ParentSeqNode->m_ChildSeqNode = nullptr;
+		m_ParentSeqNode = nullptr;
 	}
 	if (SequenceListHead == this)
 	{
@@ -823,7 +823,7 @@ DSeqNode::DSeqNode (int sequence, int modenum)
 		m_Prev = NULL;
 	}
 	GC::WriteBarrier(this);
-	m_ParentSeqNode = m_ChildSeqNode = NULL;
+	m_ParentSeqNode = m_ChildSeqNode = nullptr;
 }
 
 void DSeqNode::ActivateSequence (int sequence)