diff --git a/src/map/chat.c b/src/map/chat.c
index ced61ecfe5..05005301e7 100644
--- a/src/map/chat.c
+++ b/src/map/chat.c
@@ -167,7 +167,10 @@ int chat_joinchat(struct map_session_data* sd, int chatid, const char* pass)
 
 
 /*==========================================
- * leave a chatroom
+ * Make player *sd leave a chatroom
+ * @param *sd : player pointer
+ * @param kicked : for clif notification, kicked=1 or regular leave
+ * @return 0:sucess, 1:failed
  *------------------------------------------*/
 int chat_leavechat(struct map_session_data* sd, bool kicked)
 {
@@ -229,8 +232,8 @@ int chat_leavechat(struct map_session_data* sd, bool kicked)
 		map_delblock( &cd->bl );
 		cd->bl.x=cd->usersd[0]->bl.x;
 		cd->bl.y=cd->usersd[0]->bl.y;
-		map_addblock( &cd->bl );
-
+		if(map_addblock( &cd->bl ))
+			return 1;
 		clif_dispchat(cd,0);
 	}
 	else
@@ -241,6 +244,9 @@ int chat_leavechat(struct map_session_data* sd, bool kicked)
 
 /*==========================================
  * change a chatroom's owner
+ * @param *sd : player pointer
+ * @param *nextownername : string of new owner (name should be in chatroom)
+ * @return 0:sucess, 1:failure
  *------------------------------------------*/
 int chat_changechatowner(struct map_session_data* sd, const char* nextownername)
 {
@@ -274,7 +280,8 @@ int chat_changechatowner(struct map_session_data* sd, const char* nextownername)
 	map_delblock( &cd->bl );
 	cd->bl.x = cd->owner->x;
 	cd->bl.y = cd->owner->y;
-	map_addblock( &cd->bl );
+	if(map_addblock( &cd->bl ))
+		return 1;
 
 	// and display again
 	clif_dispchat(cd,0);
diff --git a/src/map/clif.c b/src/map/clif.c
index 301c6846c1..5833a7f325 100644
--- a/src/map/clif.c
+++ b/src/map/clif.c
@@ -2567,7 +2567,7 @@ void clif_storagelist(struct map_session_data* sd, struct item* items, int items
 		WBUFW(bufn,0)=0x995;
 		memset((char*)WBUFP(buf,4),0,24); //storename
 #endif
-		WBUFW(bufn,2)=4+nn*s;
+		WBUFW(bufn,2)=sidx+nn*s;
 		clif_send(bufn, WBUFW(bufn,2), &sd->bl, SELF);
 	}
 	for (i = 0; i < ne;) // Loop through equipable items
@@ -2583,7 +2583,7 @@ void clif_storagelist(struct map_session_data* sd, struct item* items, int items
 		WBUFW(bufn,0)=0x996;
 		memset((char*)WBUFP(bufn,4),0,24); //storename
 #endif
-		WBUFW(bufn,2)=4+nn*se;
+		WBUFW(bufn,2)=sidxe+nn*se;
 		clif_send(bufn, WBUFW(bufn,2), &sd->bl, SELF);
 	}
 
@@ -9482,7 +9482,8 @@ void clif_parse_LoadEndAck(int fd,struct map_session_data *sd)
 	// reset the callshop flag if the player changes map
 	sd->state.callshop = 0;
 
-	map_addblock(&sd->bl);
+	if(map_addblock(&sd->bl))
+		return;
 	clif_spawn(&sd->bl);
 
 	// Party
@@ -9524,7 +9525,8 @@ void clif_parse_LoadEndAck(int fd,struct map_session_data *sd)
 			clif_displaymessage(sd->fd, msg_txt(sd,666));
 			pet_menu(sd, 3); //Option 3 is return to egg.
 		} else {
-			map_addblock(&sd->pd->bl);
+			if(map_addblock(&sd->pd->bl))
+				return;
 			clif_spawn(&sd->pd->bl);
 			clif_send_petdata(sd,sd->pd,0,0);
 			clif_send_petstatus(sd);
@@ -9534,7 +9536,8 @@ void clif_parse_LoadEndAck(int fd,struct map_session_data *sd)
 
 	//homunculus [blackhole89]
 	if( merc_is_hom_active(sd->hd) ) {
-		map_addblock(&sd->hd->bl);
+		if(map_addblock(&sd->hd->bl))
+			return;
 		clif_spawn(&sd->hd->bl);
 		clif_send_homdata(sd,SP_ACK,0);
 		clif_hominfo(sd,sd->hd,1);
@@ -9547,7 +9550,8 @@ void clif_parse_LoadEndAck(int fd,struct map_session_data *sd)
 	}
 
 	if( sd->md ) {
-		map_addblock(&sd->md->bl);
+		if(map_addblock(&sd->md->bl))
+			return;
 		clif_spawn(&sd->md->bl);
 		clif_mercenary_info(sd);
 		clif_mercenary_skillblock(sd);
diff --git a/src/map/elemental.c b/src/map/elemental.c
index 33950d7892..52e46637b7 100644
--- a/src/map/elemental.c
+++ b/src/map/elemental.c
@@ -222,6 +222,12 @@ void elemental_summon_init(struct elemental_data *ed) {
 	ed->regen.state.block = 0;
 }
 
+/**
+ * Inter-serv has sent us the elemental data from sql, fill it in map-serv memory
+ * @param ele : The elemental data received from char-serv
+ * @param flag : 0:not created, 1:was saved/loaded
+ * @return 0:failed, 1:sucess
+ */
 int elemental_data_received(struct s_elemental *ele, bool flag) {
 	struct map_session_data *sd;
 	struct elemental_data *ed;
@@ -271,7 +277,8 @@ int elemental_data_received(struct s_elemental *ele, bool flag) {
 	sd->status.ele_id = ele->elemental_id;
 
 	if( ed->bl.prev == NULL && sd->bl.prev != NULL ) {
-		map_addblock(&ed->bl);
+		if(map_addblock(&ed->bl))
+			return 0;
 		clif_spawn(&ed->bl);
 		clif_elemental_info(sd);
 		clif_elemental_updatestatus(sd,SP_HP);
diff --git a/src/map/homunculus.c b/src/map/homunculus.c
index 316000cc7b..5dcb200249 100644
--- a/src/map/homunculus.c
+++ b/src/map/homunculus.c
@@ -406,6 +406,11 @@ int merc_hom_change_class(struct homun_data *hd, short class_)
 	return 1;
 }
 
+/**
+ * Make an homonculus evolve, (changing in evolution class and apply bonus)
+ * @param hd : homonculus datas
+ * @return 0:failure, 1:success
+ */
 int merc_hom_evolution(struct homun_data *hd)
 {
 	struct s_homunculus *hom;
@@ -442,7 +447,8 @@ int merc_hom_evolution(struct homun_data *hd)
 	hom->intimacy = 500;
 
 	unit_remove_map(&hd->bl, CLR_OUTSIGHT);
-	map_addblock(&hd->bl);
+	if(map_addblock(&hd->bl))
+		return 0;
 
 	clif_spawn(&hd->bl);
 	clif_emotion(&sd->bl, E_NO1);
@@ -459,6 +465,12 @@ int merc_hom_evolution(struct homun_data *hd)
 	return 1 ;
 }
 
+/**
+ * Make an homonculus mutate in renewal homon
+ * @param hd : homonculus datas
+ * @param homun_id : id to make it transform into (must be a valid homon class)
+ * @return 0:failure, 1:sucess
+ */
 int hom_mutate(struct homun_data *hd, int homun_id)
 {
 	struct s_homunculus *hom;
@@ -486,7 +498,8 @@ int hom_mutate(struct homun_data *hd, int homun_id)
 	}
 
 	unit_remove_map(&hd->bl, CLR_OUTSIGHT);
-	map_addblock(&hd->bl);
+	if(map_addblock(&hd->bl))
+		return 0;
 
 	clif_spawn(&hd->bl);
 	clif_emotion(&sd->bl, E_NO1);
@@ -827,6 +840,11 @@ void merc_hom_init_timers(struct homun_data * hd)
 	hd->masterteleport_timer = INVALID_TIMER;
 }
 
+/**
+ * Make a player spawn a homonculus (call)
+ * @param sd
+ * @return 0:failure, 1:sucess
+ */
 int merc_call_homunculus(struct map_session_data *sd)
 {
 	struct homun_data *hd;
@@ -853,7 +871,8 @@ int merc_call_homunculus(struct map_session_data *sd)
 		hd->bl.x = sd->bl.x;
 		hd->bl.y = sd->bl.y;
 		hd->bl.m = sd->bl.m;
-		map_addblock(&hd->bl);
+		if(map_addblock(&hd->bl))
+			return 0;
 		clif_spawn(&hd->bl);
 		clif_send_homdata(sd,SP_ACK,0);
 		clif_hominfo(sd,hd,1);
@@ -868,7 +887,13 @@ int merc_call_homunculus(struct map_session_data *sd)
 	return 1;
 }
 
-// Recv homunculus data from char server
+/**
+ * Receive homunculus data from char server
+ * @param account_id : owner account_id of the homon 
+ * @param sh : homonculus data from char-serv
+ * @param flag : does the creation in inter-serv was a success (0:no,1:yes)
+ * @return 0:failure, 1:sucess
+ */
 int merc_hom_recv_data(int account_id, struct s_homunculus *sh, int flag)
 {
 	struct map_session_data *sd;
@@ -899,7 +924,8 @@ int merc_hom_recv_data(int account_id, struct s_homunculus *sh, int flag)
 	hd = sd->hd;
 	if(hd && hd->homunculus.hp && !hd->homunculus.vaporize && hd->bl.prev == NULL && sd->bl.prev != NULL)
 	{
-		map_addblock(&hd->bl);
+		if(map_addblock(&hd->bl))
+			return 0;
 		clif_spawn(&hd->bl);
 		clif_send_homdata(sd,SP_ACK,0);
 		clif_hominfo(sd,hd,1);
@@ -947,6 +973,14 @@ int merc_create_homunculus_request(struct map_session_data *sd, int class_)
 	return 1;
 }
 
+/**
+ * Make a player resurect an homon (player must have one)
+ * @param sd : player pointer
+ * @param per : hp percentage to revive homon
+ * @param x : x map coordinate
+ * @param y : Y map coordinate
+ * @return 0:failure, 1:success
+ */
 int merc_resurrect_homunculus(struct map_session_data* sd, unsigned char per, short x, short y)
 {
 	struct homun_data* hd;
@@ -960,7 +994,7 @@ int merc_resurrect_homunculus(struct map_session_data* sd, unsigned char per, sh
 
 	hd = sd->hd;
 
-  	if (hd->homunculus.vaporize == HOM_ST_REST)
+	if (hd->homunculus.vaporize == HOM_ST_REST)
 		return 0; // vaporized homunculi need to be 'called'
 
 	if (!status_isdead(&hd->bl))
@@ -973,11 +1007,11 @@ int merc_resurrect_homunculus(struct map_session_data* sd, unsigned char per, sh
 		hd->bl.m = sd->bl.m;
 		hd->bl.x = x;
 		hd->bl.y = y;
-		map_addblock(&hd->bl);
+		if(map_addblock(&hd->bl))
+			return 0;
 		clif_spawn(&hd->bl);
 	}
-	status_revive(&hd->bl, per, 0);
-	return 1;
+	return status_revive(&hd->bl, per, 0);
 }
 
 void merc_hom_revive(struct homun_data *hd, unsigned int hp, unsigned int sp)
diff --git a/src/map/map.c b/src/map/map.c
index 2c8bf35d39..e25604ac13 100644
--- a/src/map/map.c
+++ b/src/map/map.c
@@ -328,7 +328,7 @@ int map_delblock(struct block_list* bl)
 	int pos;
 	nullpo_ret(bl);
 
-    // blocklist (2ways chainlist)
+	// blocklist (2ways chainlist)
 	if (bl->prev == NULL) {
 		if (bl->next != NULL) {
 			// can't delete block (already at the begining of the chain)
@@ -361,11 +361,16 @@ int map_delblock(struct block_list* bl)
 	return 0;
 }
 
-/*==========================================
+/**
  * Moves a block a x/y target position. [Skotlex]
  * Pass flag as 1 to prevent doing skill_unit_move checks
  * (which are executed by default on BL_CHAR types)
- *------------------------------------------*/
+ * @param bl : block(object) to move
+ * @param x1 : new x position
+ * @param y1 : new y position
+ * @param tick : when this was scheduled
+ * @return 0:sucess, 1:fail
+ */
 int map_moveblock(struct block_list *bl, int x1, int y1, unsigned int tick)
 {
 	int x0 = bl->x, y0 = bl->y;
@@ -404,7 +409,10 @@ int map_moveblock(struct block_list *bl, int x1, int y1, unsigned int tick)
 #endif
 	bl->x = x1;
 	bl->y = y1;
-	if (moveblock) map_addblock(bl);
+	if (moveblock) {
+		if(map_addblock(bl))
+			return 1;
+	}
 #ifdef CELL_NOSTACK
 	else map_addblcell(bl);
 #endif
@@ -677,7 +685,7 @@ int map_foreachinarea(int (*func)(struct block_list*,va_list), int16 m, int16 x0
 	int blockcount = bl_list_count, i;
 	va_list ap;
 
-	if ( m < 0 )
+	if ( m < 0 || m >= map_num)
 		return 0;
 
 	if ( x1 < x0 )
@@ -1417,13 +1425,18 @@ int map_search_freecell(struct block_list *src, int16 m, int16 *x,int16 *y, int1
 }
 
 /*==========================================
- * Add an item to location (m,x,y)
- * Parameters
- * @item_data item attributes
- * @amount quantity
- * @m, @x, @y mapid,x,y
- * @first_charid, @second_charid, @third_charid, looting priority
- * @flag: &1 MVP item. &2 do stacking check. &4 bypass droppable check.
+ * Add an item in floor to location (m,x,y) and add restriction for those who could pickup later
+ * NB : If charids are null their no restriction for pickup
+ * @param item_data : item attributes
+ * @param amount : items quantity
+ * @param m : mapid
+ * @param x : x coordinates
+ * @param y : y coordinates
+ * @param first_charid : 1st player that could loot the item (only charid that could loot for first_get_tick duration)
+ * @param second_charid :  2nd player that could loot the item (2nd charid that could loot for second_get_charid duration)
+ * @param third_charid : 3rd player that could loot the item (3rd charid that could loot for third_get_charid duration)
+ * @param flag: &1 MVP item. &2 do stacking check. &4 bypass droppable check.
+ * @return 0:failure, x:item_gid [MIN_FLOORITEM;MAX_FLOORITEM]==[2;START_ACCOUNT_NUM]
  *------------------------------------------*/
 int map_addflooritem(struct item *item_data,int amount,int16 m,int16 x,int16 y,int first_charid,int second_charid,int third_charid,int flags)
 {
@@ -1465,7 +1478,8 @@ int map_addflooritem(struct item *item_data,int amount,int16 m,int16 x,int16 y,i
 	fitem->cleartimer=add_timer(gettick()+battle_config.flooritem_lifetime,map_clearflooritem_timer,fitem->bl.id,0);
 
 	map_addiddb(&fitem->bl);
-	map_addblock(&fitem->bl);
+	if(map_addblock(&fitem->bl))
+		return 0;
 	clif_dropflooritem(fitem);
 
 	return fitem->bl.id;
diff --git a/src/map/mercenary.c b/src/map/mercenary.c
index 4fa06d6ea4..7086489af5 100644
--- a/src/map/mercenary.c
+++ b/src/map/mercenary.c
@@ -280,6 +280,12 @@ void merc_contract_init(struct mercenary_data *md)
 	md->regen.state.block = 0;
 }
 
+/**
+ * Received mercenary data from char-serv
+ * @param merc : mercenary datas
+ * @param flag : if inter-serv request was sucessfull
+ * @return 0:failure, 1:sucess
+ */
 int merc_data_received(struct s_mercenary *merc, bool flag)
 {
 	struct map_session_data *sd;
@@ -336,7 +342,8 @@ int merc_data_received(struct s_mercenary *merc, bool flag)
 
 	if( md && md->bl.prev == NULL && sd->bl.prev != NULL )
 	{
-		map_addblock(&md->bl);
+		if(map_addblock(&md->bl))
+			return 0;
 		clif_spawn(&md->bl);
 		clif_mercenary_info(sd);
 		clif_mercenary_skillblock(sd);
diff --git a/src/map/mob.c b/src/map/mob.c
index aaebb2d378..711855a931 100644
--- a/src/map/mob.c
+++ b/src/map/mob.c
@@ -122,9 +122,13 @@ static int mobdb_searchname_array_sub(struct mob_db* mob, const char *str)
 	return strcmpi(mob->jname,str);
 }
 
-/*==========================================
- *              MvP Tomb [GreenBox]
- *------------------------------------------*/
+/**
+ * Create and display a tombstone on the map
+ * @author [GreenBox]
+ * @param md : the mob to create a tombstone for
+ * @param killer : name of who has killed the mob
+ * @param time : time at wich the killed happen
+ */
 void mvptomb_create(struct mob_data *md, char *killer, time_t time)
 {
 	struct npc_data *nd;
@@ -157,7 +161,8 @@ void mvptomb_create(struct mob_data *md, char *killer, time_t time)
 		nd->u.tomb.killer_name[0] = '\0';
 
 	map_addnpc(nd->bl.m, nd);
-	map_addblock(&nd->bl);
+	if(map_addblock(&nd->bl))
+		return;
 	status_set_viewdata(&nd->bl, nd->class_);
 	status_change_init(&nd->bl);
 	unit_dataset(&nd->bl);
@@ -894,9 +899,11 @@ int mob_count_sub(struct block_list *bl, va_list ap) {
     return 1; //backward compatibility
 }
 
-/*==========================================
- * Mob spawning. Initialization is also variously here.
- *------------------------------------------*/
+/**
+ * Mob spawning. Initialization is also variously here. (Spawn a mob in a map)
+ * @param md : mob data to spawn
+ * @return 0:spawned, 1:delayed, 2:error
+ */
 int mob_spawn (struct mob_data *md)
 {
 	int i=0;
@@ -981,7 +988,8 @@ int mob_spawn (struct mob_data *md)
 	if ( md->tomb_nid )
 		mvptomb_destroy(md);
 
-	map_addblock(&md->bl);
+	if(map_addblock(&md->bl))
+		return 2;
 	if( map[md->bl.m].users )
 		clif_spawn(&md->bl);
 	skill_unit_move(&md->bl,tick,1);
@@ -2656,6 +2664,11 @@ int mob_dead(struct mob_data *md, struct block_list *src, int type)
 	return 3; //Remove from map.
 }
 
+/**
+ * Resurect a mob with x hp (reset value and respawn on map)
+ * @param md : mob pointer
+ * @param hp : hp to resurect him with, @FIXME unused atm
+ */
 void mob_revive(struct mob_data *md, unsigned int hp)
 {
 	unsigned int tick = gettick();
@@ -2666,8 +2679,10 @@ void mob_revive(struct mob_data *md, unsigned int hp)
 	md->last_pcneartime = 0;
 	memset(md->dmglog, 0, sizeof(md->dmglog));	// Reset the damage done on the rebirthed monster, otherwise will grant full exp + damage done. [Valaris]
 	md->tdmg = 0;
-	if (!md->bl.prev)
-		map_addblock(&md->bl);
+	if (!md->bl.prev){
+		if(map_addblock(&md->bl))
+			return;
+	}
 	clif_spawn(&md->bl);
 	skill_unit_move(&md->bl,tick,1);
 	mobskill_use(md, tick, MSC_SPAWN);
diff --git a/src/map/npc.c b/src/map/npc.c
index 83131b3042..cb17f846df 100644
--- a/src/map/npc.c
+++ b/src/map/npc.c
@@ -2158,7 +2158,19 @@ static void npc_parsename(struct npc_data* nd, const char* name, const char* sta
 	}
 }
 
-//Add then display an npc warp on map
+/**
+ * Add then display an npc warp on map
+ * @param name : warp unique name
+ * @param from_mapid : mapid to warp from
+ * @param from_x : x coordinate of warp
+ * @param from_y : y coordinate of warp
+ * @param xs : x lenght of warp (for trigger activation)
+ * @param ys : y lenght of warp (for trigger activation)
+ * @param to_mapindex : mapid to warp to
+ * @param to_x : x coordinate to warp to
+ * @param to_y : y coordinate to warp to
+ * @return NULL:failed creation, npc_data* new warp
+ */
 struct npc_data* npc_add_warp(char* name, short from_mapid, short from_x, short from_y, short xs, short ys, unsigned short to_mapindex, short to_x, short to_y)
 {
 	int i, flag = 0;
@@ -2197,7 +2209,8 @@ struct npc_data* npc_add_warp(char* name, short from_mapid, short from_x, short
 	nd->bl.type = BL_NPC;
 	nd->subtype = WARP;
 	npc_setcells(nd);
-	map_addblock(&nd->bl);
+	if(map_addblock(&nd->bl))
+		return NULL;
 	status_set_viewdata(&nd->bl, nd->class_);
 	status_change_init(&nd->bl);
 	unit_dataset(&nd->bl);
@@ -2208,7 +2221,18 @@ struct npc_data* npc_add_warp(char* name, short from_mapid, short from_x, short
 	return nd;
 }
 
-/// Parses a warp npc.
+/**
+ * Parses a warp npc.
+ * Line definition <from mapname>,<fromX>,<fromY>,<facing>%TAB%warp%TAB%<warp name>%TAB%<spanx>,<spany>,<to mapname>,<toX>,<toY>
+ * @param w1 : word 1 before tab (<from map name>,<fromX>,<fromY>,<facing>)
+ * @param w2 : word 2 before tab (warp), keyword that sent us in this parsing
+ * @param w3 : word 3 before tab (<warp name>)
+ * @param w4 : word 4 before tab (<spanx>,<spany>,<to mapname>,<toX>,<toY>)
+ * @param start : index to start parsing
+ * @param buffer : lines to parses
+ * @param filepath : filename with path wich we are parsing
+ * @return new index for next parsing
+ */
 static const char* npc_parse_warp(char* w1, char* w2, char* w3, char* w4, const char* start, const char* buffer, const char* filepath)
 {
 	int x, y, xs, ys, to_x, to_y, m;
@@ -2262,7 +2286,8 @@ static const char* npc_parse_warp(char* w1, char* w2, char* w3, char* w4, const
 	nd->bl.type = BL_NPC;
 	nd->subtype = WARP;
 	npc_setcells(nd);
-	map_addblock(&nd->bl);
+	if(map_addblock(&nd->bl)) //couldn't add on map
+		return strchr(start,'\n');
 	status_set_viewdata(&nd->bl, nd->class_);
 	status_change_init(&nd->bl);
 	unit_dataset(&nd->bl);
@@ -2273,7 +2298,22 @@ static const char* npc_parse_warp(char* w1, char* w2, char* w3, char* w4, const
 	return strchr(start,'\n');// continue
 }
 
-/// Parses a shop/cashshop npc.
+/**
+ * Parses a shop/cashshop npc.
+ * Line definition :
+ * <map name>,<x>,<y>,<facing>%TAB%shop%TAB%<NPC Name>%TAB%<sprite id>,<itemid>:<price>{,<itemid>:<price>...}
+ * <map name>,<x>,<y>,<facing>%TAB%itemshop%TAB%<NPC Name>%TAB%<sprite id>,<costitemid>{:<discount>},<itemid>:<price>{,<itemid>:<price>...}
+ * <map name>,<x>,<y>,<facing>%TAB%pointshop%TAB%<NPC Name>%TAB%<sprite id>,<costvariable>{:<discount>},<itemid>:<price>{,<itemid>:<price>...}
+ * @TODO missing cashshop line definition
+ * @param w1 : word 1 before tab (<from map name>,<x>,<y>,<facing>)
+ * @param w2 : word 2 before tab (shop|cashshop|itemshop|pointshop), keyword that sent us in this parsing
+ * @param w3 : word 3 before tab (<NPC Name>)
+ * @param w4 : word 4 before tab (<sprited id>,<shop definition...>)
+ * @param start : index to start parsing
+ * @param buffer : lines to parses
+ * @param filepath : filename with path wich we are parsing
+ * @return new index for next parsing
+ */
 static const char* npc_parse_shop(char* w1, char* w2, char* w3, char* w4, const char* start, const char* buffer, const char* filepath)
 {
 	//TODO: could be rewritten to NOT need this temp array [ultramage]
@@ -2419,7 +2459,8 @@ static const char* npc_parse_shop(char* w1, char* w2, char* w3, char* w4, const
 	if( m >= 0 )
 	{// normal shop npc
 		map_addnpc(m,nd);
-		map_addblock(&nd->bl);
+		if(map_addblock(&nd->bl))
+			return strchr(start,'\n');
 		status_set_viewdata(&nd->bl, nd->class_);
 		status_change_init(&nd->bl);
 		unit_dataset(&nd->bl);
@@ -2555,11 +2596,20 @@ static const char* npc_skip_script(const char* start, const char* buffer, const
 	return p+1;// return after the last '}'
 }
 
-/// Parses a npc script.
-///
-/// -%TAB%script%TAB%<NPC Name>%TAB%-1,{<code>}
-/// <map name>,<x>,<y>,<facing>%TAB%script%TAB%<NPC Name>%TAB%<sprite id>,{<code>}
-/// <map name>,<x>,<y>,<facing>%TAB%script%TAB%<NPC Name>%TAB%<sprite id>,<triggerX>,<triggerY>,{<code>}
+/**
+ * Parses a npc script.
+ * Line definition :
+ * <map name>,<x>,<y>,<facing>%TAB%script%TAB%<NPC Name>%TAB%<sprite id>,{<code>}
+ * <map name>,<x>,<y>,<facing>%TAB%script%TAB%<NPC Name>%TAB%<sprite id>,<triggerX>,<triggerY>,{<code>} * @TODO missing cashshop line definition
+ * @param w1 : word 1 before tab (<from map name>,<x>,<y>,<facing>)
+ * @param w2 : word 2 before tab (script), keyword that sent us in this parsing
+ * @param w3 : word 3 before tab (<NPC Name>)
+ * @param w4 : word 4 before tab (<sprited id>,<code>)
+ * @param start : index to start parsing
+ * @param buffer : lines to parses
+ * @param filepath : filename with path wich we are parsing
+ * @return new index for next parsing
+ */
 static const char* npc_parse_script(char* w1, char* w2, char* w3, char* w4, const char* start, const char* buffer, const char* filepath, bool runOnInit) {
 	int x, y, dir = 0, m, xs = 0, ys = 0, class_ = 0;	// [Valaris] thanks to fov
 	char mapname[32];
@@ -2648,7 +2698,8 @@ static const char* npc_parse_script(char* w1, char* w2, char* w3, char* w4, cons
 		unit_dataset(&nd->bl);
 		nd->ud.dir = dir;
 		npc_setcells(nd);
-		map_addblock(&nd->bl);
+		if(map_addblock(&nd->bl))
+			return NULL;
 		if( class_ >= 0 )
 		{
 			status_set_viewdata(&nd->bl, nd->class_);
@@ -2808,7 +2859,8 @@ const char* npc_parse_duplicate(char* w1, char* w2, char* w3, char* w4, const ch
 		unit_dataset(&nd->bl);
 		nd->ud.dir = dir;
 		npc_setcells(nd);
-		map_addblock(&nd->bl);
+		if(map_addblock(&nd->bl))
+			return end;
 		if( class_ >= 0 ) {
 			status_set_viewdata(&nd->bl, nd->class_);
 			if( map[nd->bl.m].users )
@@ -2892,7 +2944,8 @@ int npc_duplicate4instance(struct npc_data *snd, int16 m) {
 		wnd->bl.type = BL_NPC;
 		wnd->subtype = WARP;
 		npc_setcells(wnd);
-		map_addblock(&wnd->bl);
+		if(map_addblock(&wnd->bl))
+			return 1;
 		status_set_viewdata(&wnd->bl, wnd->class_);
 		status_change_init(&wnd->bl);
 		unit_dataset(&wnd->bl);
diff --git a/src/map/pet.c b/src/map/pet.c
index 9ad0daad2e..1ea052cb8a 100644
--- a/src/map/pet.c
+++ b/src/map/pet.c
@@ -411,7 +411,8 @@ int pet_birth_process(struct map_session_data *sd, struct s_pet *pet)
 		chrif_save(sd,0); //is it REALLY Needed to save the char for hatching a pet? [Skotlex]
 
 	if(sd->bl.prev != NULL) {
-		map_addblock(&sd->pd->bl);
+		if(map_addblock(&sd->pd->bl))
+			return 1;
 		clif_spawn(&sd->pd->bl);
 		clif_send_petdata(sd,sd->pd, 0,0);
 		clif_send_petdata(sd,sd->pd, 5,battle_config.pet_hair_style);
@@ -452,7 +453,8 @@ int pet_recv_petdata(int account_id,struct s_pet *p,int flag)
 	} else {
 		pet_data_init(sd,p);
 		if(sd->pd && sd->bl.prev != NULL) {
-			map_addblock(&sd->pd->bl);
+			if(map_addblock(&sd->pd->bl))
+				return 1;
 			clif_spawn(&sd->pd->bl);
 			clif_send_petdata(sd,sd->pd,0,0);
 			clif_send_petdata(sd,sd->pd,5,battle_config.pet_hair_style);
diff --git a/src/map/skill.c b/src/map/skill.c
index 3279d23cb4..5ea6dd9105 100644
--- a/src/map/skill.c
+++ b/src/map/skill.c
@@ -6124,7 +6124,8 @@ int skill_castend_nodamage_id (struct block_list *src, struct block_list *bl, ui
 			skill_get_splash(skill_id, skill_lv), splash_target(src),
 			src, skill_id, skill_lv, tick, flag|i,
 			skill_castend_damage_id);
-		map_addblock(src);
+		if(map_addblock(src))
+			return 1;
 		status_damage(src, src, sstatus->max_hp,0,0,1);
 		break;
 
@@ -15985,7 +15986,8 @@ struct skill_unit *skill_initunit (struct skill_unit_group *group, int idx, int
 
 	idb_put(skillunit_db, unit->bl.id, unit);
 	map_addiddb(&unit->bl);
-	map_addblock(&unit->bl);
+	if(map_addblock(&unit->bl))
+		return NULL;
 
 	// perform oninit actions
 	switch (group->skill_id) {
diff --git a/src/map/unit.c b/src/map/unit.c
index e4cfcd363d..47e225613b 100644
--- a/src/map/unit.c
+++ b/src/map/unit.c
@@ -199,7 +199,8 @@ int unit_check_start_teleport_timer(struct block_list *sbl)
 		case BL_PET : max_dist = AREA_SIZE; break;
 		case BL_MER : max_dist = MAX_MER_DISTANCE; break;
 	}
-	if(msd && max_dist){ // If there is a master and it's a valid type
+	// If there is a master and it's a valid type 
+	if(msd && (msd->bl.type&BL_PC) && max_dist){ ///TODO the bl.type is an hotfix please dig it to remove it
 		int *msd_tid = unit_get_masterteleport_timer(sbl);
 		if(msd_tid == NULL) return 0;
 		if (!check_distance_bl(&msd->bl, sbl, max_dist)) {
@@ -941,7 +942,7 @@ int unit_blown(struct block_list* bl, int dx, int dy, int count, int flag)
 * @param x: Destination cell X
 * @param y: Destination cell Y
 * @param type: Clear type used in clif_clearunit_area()
-* @return Success(0); Failed(1); Error(2); unit_remove_map() Failed(3)
+* @return Success(0); Failed(1); Error(2); unit_remove_map() Failed(3); map_addblock Failed(4)
 **/
 int unit_warp(struct block_list *bl,short m,short x,short y,clr_type type)
 {
@@ -1001,7 +1002,8 @@ int unit_warp(struct block_list *bl,short m,short x,short y,clr_type type)
 	bl->y=ud->to_y=y;
 	bl->m=m;
 
-	map_addblock(bl);
+	if(map_addblock(bl))
+		return 4; //error on adding bl to map
 	clif_spawn(bl);
 	skill_unit_move(bl,gettick(),1);