Correct a map crash from slaves_inherit_mode (#8721)

* Correct a map crash from slaves_inherit_mode
* Fixes #8511.
* Resolves an issue with sending player session data as mob data to status_calc_slave_mode().
* Cleanup status_calc_slave_mode() to use pass by reference.
Thanks to @jamesandrewww!

---------

Co-authored-by: Lemongrass3110 <lemongrass@kstp.at>

src/map/mob.cpp

@@ -3677,7 +3677,7 @@ int mob_summonslave(struct mob_data *md2,int *value,int amount,uint16 skill_id)
 			md->status.hp = md->status.max_hp*hp_rate/100;
 
 		if (skill_id == NPC_SUMMONSLAVE) // Only appies to NPC_SUMMONSLAVE
-			status_calc_slave_mode(md, md2); // Inherit the aggressive mode of the master.
+			status_calc_slave_mode(*md); // Inherit the aggressive mode of the master.
 
 		if (md2->state.copy_master_mode)
 			md->status.mode = md2->status.mode;

src/map/status.cpp

@@ -2780,7 +2780,7 @@ int status_calc_mob_(struct mob_data* md, uint8 opt)
 	}
 
 	if (flag&32)
-		status_calc_slave_mode(md, map_id2md(md->master_id));
+		status_calc_slave_mode(*md);
 
 	if (flag&1) { // Increase from mobs leveling up [Valaris]
 		int diff = md->level - md->db->lv;
@@ -8940,27 +8940,26 @@ static int status_calc_mode(struct block_list *bl, status_change *sc, int mode)
 /**
  * Changes the mode of a slave mob
  * @param md: Slave mob whose mode to change
- * @param mmd: Master of slave mob
  */
-void status_calc_slave_mode(struct mob_data *md, struct mob_data *mmd)
+void status_calc_slave_mode(mob_data& md)
 {
 	switch (battle_config.slaves_inherit_mode) {
 		case 1: //Always aggressive
-			if (!status_has_mode(&md->status,MD_AGGRESSIVE))
-				sc_start4(nullptr, &md->bl, SC_MODECHANGE, 100, 1, 0, MD_AGGRESSIVE, 0, 0);
+			if (!status_has_mode(&md.status,MD_AGGRESSIVE))
+				sc_start4(nullptr, &md.bl, SC_MODECHANGE, 100, 1, 0, MD_AGGRESSIVE, 0, 0);
 			break;
 		case 2: //Always passive
-			if (status_has_mode(&md->status,MD_AGGRESSIVE))
-				sc_start4(nullptr, &md->bl, SC_MODECHANGE, 100, 1, 0, 0, MD_AGGRESSIVE, 0);
+			if (status_has_mode(&md.status,MD_AGGRESSIVE))
+				sc_start4(nullptr, &md.bl, SC_MODECHANGE, 100, 1, 0, 0, MD_AGGRESSIVE, 0);
 			break;
 		case 4: // Overwrite with slave mode
-			sc_start4(nullptr, &md->bl, SC_MODECHANGE, 100, 1, MD_CANMOVE|MD_NORANDOMWALK|MD_CANATTACK, 0, 0, 0);
+			sc_start4(nullptr, &md.bl, SC_MODECHANGE, 100, 1, MD_CANMOVE|MD_NORANDOMWALK|MD_CANATTACK, 0, 0, 0);
 			break;
 		default: //Copy master
-			if (status_has_mode(&mmd->status,MD_AGGRESSIVE))
-				sc_start4(nullptr, &md->bl, SC_MODECHANGE, 100, 1, 0, MD_AGGRESSIVE, 0, 0);
+			if (block_list* mbl = map_id2bl(md.master_id); mbl != nullptr && status_has_mode(status_get_status_data(*mbl), MD_AGGRESSIVE))
+				sc_start4(nullptr, &md.bl, SC_MODECHANGE, 100, 1, 0, MD_AGGRESSIVE, 0, 0);
 			else
-				sc_start4(nullptr, &md->bl, SC_MODECHANGE, 100, 1, 0, 0, MD_AGGRESSIVE, 0);
+				sc_start4(nullptr, &md.bl, SC_MODECHANGE, 100, 1, 0, 0, MD_AGGRESSIVE, 0);
 			break;
 	}
 }

src/map/status.hpp

@@ -3540,7 +3540,7 @@ void status_calc_regen(struct block_list *bl, struct status_data *status, struct
 void status_calc_regen_rate(struct block_list *bl, struct regen_data *regen, status_change *sc);
 void status_calc_state(struct block_list *bl, status_change *sc, std::bitset<SCS_MAX> flag, bool start);
 
-void status_calc_slave_mode(struct mob_data *md, struct mob_data *mmd);
+void status_calc_slave_mode(mob_data& md);
 
 bool status_check_skilluse(struct block_list *src, struct block_list *target, uint16 skill_id, int flag);
 int status_check_visibility(struct block_list *src, struct block_list *target);