Fixed `npc_cashshop_buy` for 2010-11-16 client or older

* Failed to buy item from `itemshop` and `pointshop` NPC
* Thanks to Anime s2 that notices this

Signed-off-by: Cydh Ramdh <cydh@pservero.com>

src/map/npc.c

@@ -1366,6 +1366,63 @@ int npc_buysellsel(struct map_session_data* sd, int id, int type)
 	return 0;
 }
 
+/** Payment Process for NPCTYPE_CASHSHOP, NPCTYPE_ITEMSHOP, and NPCTYPE_POINTSHOP
+ * @param nd NPC Shop data
+ * @param price Price must be paid
+ * @param points Total points that player has
+ * @param sd Player data
+ * @return e_CASHSHOP_ACK
+ **/
+static enum e_CASHSHOP_ACK npc_cashshop_process_payment(struct npc_data *nd, int price, int points, struct map_session_data *sd) {
+	int cost[2] = { 0, 0 };
+
+	npc_shop_currency_type(sd, nd, cost, false);
+
+	switch(nd->subtype) {
+		case NPCTYPE_CASHSHOP:
+			if (cost[1] < points || cost[0] < (price - points))
+				return ERROR_TYPE_MONEY;
+			pc_paycash(sd, price, points, LOG_TYPE_NPC);
+			break;
+		case NPCTYPE_ITEMSHOP:
+			{
+				struct item_data *id = itemdb_exists(nd->u.shop.itemshop_nameid);
+
+				if (cost[0] < (price - points)) {
+					char output[CHAT_SIZE_MAX];
+
+					memset(output, '\0', sizeof(output));
+
+					sprintf(output, msg_txt(sd, 712), (id) ? id->jname : "NULL", (id) ? id->nameid : 0); // You do not have enough %s (%hu).
+					clif_colormes(sd->fd, color_table[COLOR_RED], output);
+					return ERROR_TYPE_PURCHASE_FAIL;
+				}
+				if (id)
+					pc_delitem(sd, pc_search_inventory(sd, nd->u.shop.itemshop_nameid), price - points, 0, 0, LOG_TYPE_NPC);
+				else
+					ShowWarning("Failed to delete item %hu from itemshop NPC '%s' (%s, %d, %d)!\n", nd->u.shop.itemshop_nameid, nd->exname, map[nd->bl.m].name, nd->bl.x, nd->bl.y);
+			}
+			break;
+		case NPCTYPE_POINTSHOP:
+			{
+				char output[CHAT_SIZE_MAX];
+
+				memset(output, '\0', sizeof(output));
+
+				if (cost[0] < (price - points)) {
+					sprintf(output, msg_txt(sd, 713), nd->u.shop.pointshop_str); // You do not have enough '%s'.
+					clif_colormes(sd->fd, color_table[COLOR_RED], output);
+					return ERROR_TYPE_PURCHASE_FAIL;
+				}
+				pc_setreg2(sd, nd->u.shop.pointshop_str, cost[0] - (price - points));
+				sprintf(output, msg_txt(sd, 716), nd->u.shop.pointshop_str, cost[0] - (price - points)); // Your '%s' is now: %d
+				clif_disp_onlyself(sd, output, strlen(output) + 1);
+			}
+			break;
+	}
+	return ERROR_TYPE_NONE;
+}
+
 /**
  * Cash Shop Buy List for clients 2010-11-16 and newer
  * @param sd: Player data
@@ -1376,9 +1433,10 @@ int npc_buysellsel(struct map_session_data* sd, int id, int type)
  */
 int npc_cashshop_buylist(struct map_session_data *sd, int points, int count, unsigned short* item_list)
 {
-	int i, j, amount, new_, w, vt, cost[2] = { 0, 0 };
+	int i, j, amount, new_, w, vt;
 	unsigned short nameid;
 	struct npc_data *nd = (struct npc_data *)map_id2bl(sd->npc_shopid);
+	enum e_CASHSHOP_ACK res;
 
 	if( !nd || ( nd->subtype != NPCTYPE_CASHSHOP && nd->subtype != NPCTYPE_ITEMSHOP && nd->subtype != NPCTYPE_POINTSHOP ) )
 		return ERROR_TYPE_NPC;
@@ -1429,51 +1487,8 @@ int npc_cashshop_buylist(struct map_session_data *sd, int points, int count, uns
 		return ERROR_TYPE_INVENTORY_WEIGHT;
 	if( points > vt ) points = vt;
 
-	// Payment Process ----------------------------------------------------
-	npc_shop_currency_type(sd, nd, cost, false);
-
-	switch(nd->subtype) {
-		case NPCTYPE_CASHSHOP:
-			if (cost[1] < points || cost[0] < (vt - points))
-				return ERROR_TYPE_MONEY;
-			pc_paycash(sd, vt, points, LOG_TYPE_NPC);
-			break;
-		case NPCTYPE_ITEMSHOP:
-		{
-			struct item_data *id = itemdb_exists(nd->u.shop.itemshop_nameid);
-
-			if (cost[0] < (vt - points)) {
-				char output[CHAT_SIZE_MAX];
-
-				memset(output, '\0', sizeof(output));
-
-				sprintf(output, msg_txt(sd, 712), (id) ? id->jname : "NULL", (id) ? id->nameid : 0); // You do not have enough %s (%hu).
-				clif_colormes(sd->fd, color_table[COLOR_RED], output);
-				return ERROR_TYPE_PURCHASE_FAIL;
-			}
-			if (id)
-				pc_delitem(sd, pc_search_inventory(sd, nd->u.shop.itemshop_nameid), vt - points, 0, 0, LOG_TYPE_NPC);
-			else
-				ShowWarning("Failed to delete item %hu from itemshop NPC '%s' (%s, %d, %d)!\n", nd->u.shop.itemshop_nameid, nd->exname, map[nd->bl.m].name, nd->bl.x, nd->bl.y);
-		}
-			break;
-		case NPCTYPE_POINTSHOP:
-		{
-			char output[CHAT_SIZE_MAX];
-
-			memset(output, '\0', sizeof(output));
-
-			if (cost[0] < (vt - points)) {
-				sprintf(output, msg_txt(sd, 713), nd->u.shop.pointshop_str); // You do not have enough '%s'.
-				clif_colormes(sd->fd, color_table[COLOR_RED], output);
-				return ERROR_TYPE_PURCHASE_FAIL;
-			}
-			pc_setreg2(sd, nd->u.shop.pointshop_str, cost[0] - (vt - points));
-			sprintf(output, msg_txt(sd, 716), nd->u.shop.pointshop_str, cost[0] - (vt - points)); // Your '%s' is now: %d
-			clif_disp_onlyself(sd, output, strlen(output) + 1);
-		}
-			break;
-	}
+	if ((res = npc_cashshop_process_payment(nd, vt, points, sd)) != ERROR_TYPE_NONE)
+		return res;
 
 	// Delivery Process ----------------------------------------------------
 	for( i = 0; i < count; i++ ) {
@@ -1573,6 +1588,7 @@ int npc_cashshop_buy(struct map_session_data *sd, unsigned short nameid, int amo
 	struct npc_data *nd = (struct npc_data *)map_id2bl(sd->npc_shopid);
 	struct item_data *item;
 	int i, price, w;
+	enum e_CASHSHOP_ACK res;
 
 	if( amount <= 0 )
 		return ERROR_TYPE_ITEM_ID;
@@ -1580,7 +1596,7 @@ int npc_cashshop_buy(struct map_session_data *sd, unsigned short nameid, int amo
 	if( points < 0 )
 		return ERROR_TYPE_MONEY;
 
-	if( !nd || nd->subtype != NPCTYPE_CASHSHOP )
+	if( !nd || (nd->subtype != NPCTYPE_CASHSHOP && nd->subtype != NPCTYPE_ITEMSHOP && nd->subtype != NPCTYPE_POINTSHOP) )
 		return ERROR_TYPE_NPC;
 
 	if( sd->state.trading )
@@ -1630,10 +1646,8 @@ int npc_cashshop_buy(struct map_session_data *sd, unsigned short nameid, int amo
 	if( points > price )
 		points = price;
 
-	if( (sd->kafraPoints < points) || (sd->cashPoints < price - points) )
-		return ERROR_TYPE_MONEY;
-
-	pc_paycash(sd, price, points, LOG_TYPE_NPC);
+	if ((res = npc_cashshop_process_payment(nd, price, points, sd)) != ERROR_TYPE_NONE)
+		return res;
 
 	if( !pet_create_egg(sd, nameid) ) {
 		struct item item_tmp;