Add sell all button to NPC trade

src/client/const.h

@@ -352,6 +352,7 @@ namespace Otc
         GameNewSpeedLaw = 36,
         GameForceFirstAutoWalkStep = 37,
         GameMinimapRemove = 38,
+        GameDoubleShopSellAmount = 39,
         // 51-100 reserved to be defined in lua
         LastGameFeature = 101
     };

src/client/protocolgameparse.cpp

@@ -698,9 +698,14 @@ void ProtocolGame::parsePlayerGoods(const InputMessagePtr& msg)
     int size = msg->getU8();
     for(int i = 0; i < size; i++) {
         int itemId = msg->getU16();
-        int count = msg->getU8();
+        int amount;
 
-        goods.push_back(std::make_tuple(Item::create(itemId), count));
+        if(g_game.getFeature(Otc::GameDoubleShopSellAmount))
+            amount = msg->getU16();
+        else
+            amount = msg->getU8();
+
+        goods.push_back(std::make_tuple(Item::create(itemId), amount));
     }
 
     g_game.processPlayerGoods(money, goods);

src/client/protocolgamesend.cpp

@@ -319,7 +319,10 @@ void ProtocolGame::sendSellItem(int itemId, int subType, int amount, bool ignore
     msg->addU8(Proto::ClientSellItem);
     msg->addU16(itemId);
     msg->addU8(subType);
-    msg->addU8(amount);
+    if(g_game.getFeature(Otc::GameDoubleShopSellAmount))
+        msg->addU16(amount);
+    else
+        msg->addU8(amount);
     msg->addU8(ignoreEquipped ? 0x01 : 0x00);
     send(msg);
 }