Double attack on Emperium is miss on rAthena. This diff fixes for issue #217 (https://github.com/rathena/rathena/issues/217). Reason for this change, see my comment below.

Double_attack_on_Emperium.diff

diff --git a/src/map/battle.c b/src/map/battle.c
index 825436e..70a3846 100644
--- a/src/map/battle.c
+++ b/src/map/battle.c
@@ -3282,9 +3282,10 @@ static struct Damage battle_calc_multi_attack(struct Damage wd, struct block_lis
 			|| ( sd->bonus.double_rate > 0 && sd->weapontype1 != W_FIST ) //Will fail bare-handed
 			|| ( sc && sc->data[SC_KAGEMUSYA] && sd->weapontype1 != W_FIST )) // Need confirmation
 		{	//Success chance is not added, the higher one is used [Skotlex]
-                        int max_rate = max(5*skill_lv,sd->bonus.double_rate);
-                        if(sc && sc->data[SC_KAGEMUSYA]) max_rate= max(max_rate,sc->data[SC_KAGEMUSYA]->val1*3);
-                        
+			int max_rate = max(5*skill_lv,sd->bonus.double_rate);
+			if(sc && sc->data[SC_KAGEMUSYA])
+				max_rate= max(max_rate,sc->data[SC_KAGEMUSYA]->val1*3);
+
 			if( rnd()%100 < max_rate ) {
 				wd.div_ = skill_get_num(TF_DOUBLE,skill_lv?skill_lv:1);
 				wd.type = DMG_MULTI_HIT;
@@ -4783,13 +4784,8 @@ struct Damage battle_calc_attack_plant(struct Damage wd, struct block_list *src,
 	//Plants receive 1 damage when hit
 	if( attack_hits || wd.damage > 0 )
 		wd.damage = 1; //In some cases, right hand no need to have a weapon to deal a damage
-	if( is_attack_left_handed(src, skill_id) && (attack_hits || wd.damage2 > 0) ) {
-		if(sd->status.weapon == W_KATAR)
-			wd.damage2 = 0; //No backhand damage against plants
-		else {
-			wd.damage2 = 1; //Deal 1 HP damage as long as there is a weapon in the left hand
-		}
-	}
+	if( is_attack_left_handed(src, skill_id) && (attack_hits || wd.damage2 > 0) )
+		wd.damage2 = 1; //Deal 1 HP damage as long as there is a weapon in the left hand
 
 	if (attack_hits && target->type == BL_MOB) {
 		struct status_change *sc = status_get_sc(target);
@@ -4805,7 +4801,13 @@ struct Damage battle_calc_attack_plant(struct Damage wd, struct block_list *src,
 			wd.damage = wd.damage2 = 0;
 			return wd;
 		}
-		if (wd.damage > 0) {
+		wd = battle_apply_div_fix(wd, skill_id);
+		//If there is left hand damage, total damage can never exceed 2, even on multiple hits
+		if(wd.damage > 1 && wd.damage2 > 0) {
+			wd.damage = 1;
+			wd.damage2 = 1;
+		}
+		if (wd.damage - wd.div_ > 0) {
 			wd.damage = battle_attr_fix(src, target, wd.damage, right_element, tstatus->def_ele, tstatus->ele_lv);
 			wd.damage = battle_calc_gvg_damage(src, target, wd.damage, skill_id, wd.flag);
 		} else if (wd.damage2 > 0) {
@@ -7721,7 +7723,7 @@ int battle_check_target( struct block_list *src, struct block_list *target,int f
 						return 0; // You can't target anything out of your duel
 				}
 			}
-			if( map_flag_gvg(m) && !sd->status.guild_id && t_bl->type == BL_MOB && ((TBL_MOB*)t_bl)->mob_id == MOBID_EMPERIUM )
+			if( map_flag_gvg2(m) && !sd->status.guild_id && t_bl->type == BL_MOB && ((TBL_MOB*)t_bl)->mob_id == MOBID_EMPERIUM )
 				return 0; //If you don't belong to a guild, can't target emperium.
 			if( t_bl->type != BL_PC )
 				state |= BCT_ENEMY; //Natural enemy.
diff --git a/src/map/clif.c b/src/map/clif.c
index ae199a2..cc79db4 100644
--- a/src/map/clif.c
+++ b/src/map/clif.c
@@ -4704,13 +4704,17 @@ int clif_damage(struct block_list* src, struct block_list* dst, unsigned int tic
 		}
 	}
 
+	// Removes 'miss' in Castles map because of the damage != div limit
+	if (map_flag_gvg2(dst->m) && div > damage)
+		damage = div;
+
 	WBUFW(buf,0) = cmd;
 	WBUFL(buf,2) = src->id;
 	WBUFL(buf,6) = dst->id;
 	WBUFL(buf,10) = tick;
 	WBUFL(buf,14) = sdelay;
 	WBUFL(buf,18) = ddelay;
-	if (battle_config.hide_woe_damage && map_flag_gvg(src->m)) {
+	if (battle_config.hide_woe_damage && map_flag_gvg2(src->m)) {
 		WBUFW(buf,22) = damage ? div : 0;
 		WBUFW(buf,27+offset) = damage2 ? div : 0;
 	} else {
@@ -5451,7 +5455,7 @@ int clif_skill_damage(struct block_list *src,struct block_list *dst,unsigned int
 	WBUFL(buf,12)=tick;
 	WBUFL(buf,16)=sdelay;
 	WBUFL(buf,20)=ddelay;
-	if (battle_config.hide_woe_damage && map_flag_gvg(src->m)) {
+	if (battle_config.hide_woe_damage && map_flag_gvg2(src->m)) {
 		WBUFW(buf,24)=damage?div:0;
 	} else {
 		WBUFW(buf,24)=damage;
@@ -5482,7 +5486,7 @@ int clif_skill_damage(struct block_list *src,struct block_list *dst,unsigned int
 	WBUFL(buf,12)=tick;
 	WBUFL(buf,16)=sdelay;
 	WBUFL(buf,20)=ddelay;
-	if (battle_config.hide_woe_damage && map_flag_gvg(src->m)) {
+	if (battle_config.hide_woe_damage && map_flag_gvg2(src->m)) {
 		WBUFL(buf,24)=damage?div:0;
 	} else {
 		WBUFL(buf,24)=damage;
@@ -5549,7 +5553,7 @@ int clif_skill_damage2(struct block_list *src,struct block_list *dst,unsigned in
 	WBUFL(buf,20)=ddelay;
 	WBUFW(buf,24)=dst->x;
 	WBUFW(buf,26)=dst->y;
-	if (battle_config.hide_woe_damage && map_flag_gvg(src->m)) {
+	if (battle_config.hide_woe_damage && map_flag_gvg2(src->m)) {
 		WBUFW(buf,28)=damage?div:0;
 	} else {
 		WBUFW(buf,28)=damage;

• Fixes for issue #217 (rathena/rathena#217)
• Just found out that Katar still deals 2 damage instead of 1
• If you're asking why if (wd.damage - wd.div_ > 0) {, as long as the damage 1, if it reduced by map modifier, it's still 1. But if the damage is 2 (by DA) or more (by Fear Breeze) client will shows miss because of damage may reduced to less than div