From 91b2fee45ded14bd70cd588f2c9d9d01dfcaf8c5 Mon Sep 17 00:00:00 2001
From: Wuzzy <almikes@aol.com>
Date: Mon, 12 Jun 2017 19:06:33 +0200
Subject: [PATCH] Fix hoppers placing >1 lava buckets into furnace

---
 mods/ITEMS/mcl_hoppers/init.lua | 33 +++++++++++++++++++++++++--------
 1 file changed, 25 insertions(+), 8 deletions(-)

diff --git a/mods/ITEMS/mcl_hoppers/init.lua b/mods/ITEMS/mcl_hoppers/init.lua
index e749512838..92beb3d951 100644
--- a/mods/ITEMS/mcl_hoppers/init.lua
+++ b/mods/ITEMS/mcl_hoppers/init.lua
@@ -235,12 +235,12 @@ minetest.register_abm({
 
 -- Iterates through all items in the given inventory and
 -- return the slot of the first item which matches a condition
-local get_eligible_transfer_item = function(inventory, list, condition)
-	local size = inventory:get_size(list)
+local get_eligible_transfer_item = function(src_inventory, src_list, dst_inventory, dst_list, condition)
+	local size = src_inventory:get_size(src_list)
 	local stack
 	for i=1, size do
-		stack = inventory:get_stack(list, i)
-		if not stack:is_empty() and condition(stack) then
+		stack = src_inventory:get_stack(src_list, i)
+		if not stack:is_empty() and condition(stack, src_inventory, src_list, dst_inventory, dst_list) then
 			return i
 		end
 	end
@@ -253,6 +253,21 @@ local is_not_shulker_box = function(itemstack)
 	return g == 0 or g == nil
 end
 
+-- Returns true if itemstack is fuel, but not for lava bucket if destination already has one
+local is_transferrable_fuel = function(itemstack, src_inventory, src_list, dst_inventory, dst_list)
+	if mcl_util.is_fuel(itemstack) then
+		if itemstack:get_name() == "bucket:bucket_lava" then
+			return dst_inventory:is_empty(dst_list)
+		else
+			return true
+		end
+	else
+		return false
+	end
+end
+
+
+
 minetest.register_abm({
 	label = "Hopper/container item exchange",
 	nodenames = {"mcl_hoppers:hopper"},
@@ -288,7 +303,8 @@ minetest.register_abm({
 		if g == 3 then
 			-- For shulker boxes, only select non-shulker boxes
 			local sinv = minetest.get_inventory({type="node", pos = pos})
-			slot_id = get_eligible_transfer_item(sinv, "main", is_not_shulker_box)
+			local dinv = minetest.get_inventory({type="node", pos = downpos})
+			slot_id = get_eligible_transfer_item(sinv, "main", dinv, "main", is_not_shulker_box)
 		end
 		if slot_id then
 			mcl_util.move_item_container(pos, "main", slot_id, downpos)
@@ -296,7 +312,6 @@ minetest.register_abm({
 	end,
 })
 
-
 minetest.register_abm({
 	label = "Side-hopper/container item exchange",
 	nodenames = {"mcl_hoppers:hopper_side"},
@@ -338,14 +353,16 @@ minetest.register_abm({
 		elseif g == 3 then
 			-- Put non-shulker boxes into shulker box
 			local sinv = minetest.get_inventory({type="node", pos = pos})
-			local slot_id = get_eligible_transfer_item(sinv, "main", is_not_shulker_box)
+			local dinv = minetest.get_inventory({type="node", pos = front})
+			local slot_id = get_eligible_transfer_item(sinv, "main", dinv, "main", is_not_shulker_box)
 			if slot_id then
 				mcl_util.move_item_container(pos, "main", slot_id, front)
 			end
 		elseif g == 4 then
 			-- Put fuel into fuel slot
 			local sinv = minetest.get_inventory({type="node", pos = pos})
-			local slot_id = get_eligible_transfer_item(sinv, "main", mcl_util.is_fuel)
+			local dinv = minetest.get_inventory({type="node", pos = front})
+			local slot_id, stack = get_eligible_transfer_item(sinv, "main", dinv, "fuel", is_transferrable_fuel)
 			if slot_id then
 				mcl_util.move_item_container(pos, "main", slot_id, front, "fuel")
 			end