fix crash when a summon would attack before despawning (#28)

1 files changed, 14 insertions, 6 deletions

diff --git a/src/crmain.cc b/src/crmain.cc
index f2f13ac..15c72b8 100644
--- a/src/crmain.cc
+++ b/src/crmain.cc
@@ -457,12 +457,12 @@ int TCreature::Damage(TCreature *Attacker, int Damage, int DamageType){
 		return 0;
 	}
 
-	if(this->Type == PLAYER){
-		if(this->Connection != NULL && Attacker != NULL){
+	if(Attacker != NULL && this->Type == PLAYER){
+		if(this->Connection != NULL){
 			SendMarkCreature(this->Connection, Attacker->ID, COLOR_BLACK);
 		}
 
-		if(Attacker != NULL && Attacker->Type == PLAYER
+		if(Attacker->Type == PLAYER
 				&& DamageType != DAMAGE_POISON_PERIODIC
 				&& DamageType != DAMAGE_FIRE_PERIODIC
 				&& DamageType != DAMAGE_ENERGY_PERIODIC){
@@ -479,7 +479,15 @@ int TCreature::Damage(TCreature *Attacker, int Damage, int DamageType){
 
 		uint32 MasterID = Attacker->GetMaster();
 		if(MasterID != 0){
-			Responsible = GetCreature(MasterID);
+			// NOTE(fusion): This is very subtle but we could hit a case where the
+			// master logs out or dies but the summon has a ToDoAttack queued, in
+			// which case it would try to attack before checking whether it should
+			// despawn in `TMonster::IdleStimulus`, causing `Responsible` to be NULL
+			// even though `Attacker` is not.
+			TCreature *Master = GetCreature(MasterID);
+			if(Master != NULL){
+				Responsible = Master;
+			}
 		}
 
 		Attacker->BlockLogout(60, this->Type == PLAYER);
@@ -653,8 +661,8 @@ int TCreature::Damage(TCreature *Attacker, int Damage, int DamageType){
 	}
 
 	this->Skills[SKILL_HITPOINTS]->Change(-Damage);
-	if(Responsible != NULL){
-		ASSERT(Attacker != NULL);
+	if(Attacker != NULL){
+		ASSERT(Responsible != NULL);
 		if(Responsible == Attacker){
 			this->Combat.AddDamageToCombatList(Attacker->ID, Damage);
 		}else{