Added merchant close callback to close the shopping list when the merchant window closes, only if the shopping list is empty.

diff --git a/CauldronMain.lua b/CauldronMain.lua
index 1687d82..f3e6673 100644
--- a/CauldronMain.lua
+++ b/CauldronMain.lua
@@ -193,7 +193,7 @@ function Cauldron:OnEnable()
 --	self:RegisterEvent("PLAYERBANKBAGSLOTS_CHANGED");
 	self:RegisterEvent("MERCHANT_SHOW", "OnMerchantShow");
 --	self:RegisterEvent("MERCHANT_UPDATE");
---	self:RegisterEvent("MERCHANT_CLOSED");
+	self:RegisterEvent("MERCHANT_CLOSED", "OnMerchantClose");
 	self:RegisterEvent("BAG_UPDATE", "OnBagUpdate");
 --	self:RegisterEvent("TRAINER_CLOSED");
 --	self:RegisterEvent("PLAYER_REGEN_DISABLED");
@@ -477,10 +477,13 @@ function Cauldron:OnMerchantShow()
 	self:debug("OnMerchantShow enter");
 --@end-alpha@

-	Cauldron:ShowShoppingList();
-
-	if Cauldron.db.realm.userdata[Cauldron.vars.playername].options.autoBuy then
-		CauldronShopping:AutoBuyShoppingItems(Cauldron.db.realm.shopping, Cauldron.vars.playername);
+	-- check if there's anything in the shopping list
+	if CauldronShopping:ContainsItems(Cauldron.db.realm.shopping) then
+		Cauldron:ShowShoppingList();
+
+		if Cauldron.db.realm.userdata[Cauldron.vars.playername].options.autoBuy then
+			CauldronShopping:AutoBuyShoppingItems(Cauldron.db.realm.shopping, Cauldron.vars.playername);
+		end
 	end

 --@alpha@
@@ -488,6 +491,20 @@ function Cauldron:OnMerchantShow()
 --@end-alpha@
 end

+function Cauldron:OnMerchantClose()
+--@alpha@
+	self:debug("OnMerchantClose enter");
+--@end-alpha@
+
+	if not CauldronShopping:ContainsItems(Cauldron.db.realm.shopping) then
+		Cauldron:HideShoppingList();
+	end
+
+--@alpha@
+	self:debug("OnMerchantClose exit");
+--@end-alpha@
+end
+
 function Cauldron:OnBankOpened()
 --@alpha@
 	self:debug("OnBankOpened enter");