added count parameter to room_for_item() and return available room from room_for_*()

API

@@ -36,9 +36,14 @@ node definition implements all or some of these functions:
 		-- liquid should be the name of a source liquid (in bucket.liquids of bucket mod)
 		-- 1 bucket or source block is 1000 millibuckets
 
-	node_io_room_for_item(pos, node, side, itemstack) -> bool
-	node_io_room_for_liquid(pos, node, side, liquid, millibuckets) -> bool
-		-- use millibuckets=1 to check if not full, then call put_liquid() with actual amount to transfer, leftover
+	node_io_room_for_item(pos, node, side, itemstack, count) -> int
+		-- ignore count in itemstack, only use the count parameter
+		-- returns count if inventory can hold entire stack, else returns amount the inventory can hold
+		-- use count=1 to check if not full, then call put_item() with actual amount to transfer
+		-- the non-zero return count is needed by transfer nodes that take from one inventory node and put in another inventory node
+	node_io_room_for_liquid(pos, node, side, liquid, millibuckets) -> int
+		-- returns millibuckets if inventory can hold entire amount, else returns amount the inventory can hold
+		-- use millibuckets=1 to check if not full, then call put_liquid() with actual amount to transfer
 		-- use millibuckets=1000 with room_for_liquid() and put_liquid() to only insert full buckets
 
 
@@ -83,6 +88,11 @@ API has utility functions for standard inventory nodes to easily implement the A
 		-- returns a "fake" itemstack based on stack but only containing count items
 		-- this can be used with node_io.room_for_item(), and then use itemstack=stack:take_item(count) to get a real itemstack
 
+	node_io.compare_itemstack(itemstack1, itemstack2) -> bool
+		-- returns true if both itemstacks are identical, excluding count
+
+	node_io.room_for_item_in_inventory(inv, inv_name, itemstack, count) -> int
+		-- call from node_io_room_for_item()
 	node_io.get_inventory_size(pos, inv_name)
 		-- call from node_io_get_item_size()
 	node_io.get_inventory_name(pos, inv_name, index)

init.lua

@@ -61,14 +61,14 @@ node_io.can_take_liquid = function(pos, node, side)
 	return ndef.node_io_can_take_liquid(pos, node, side)
 end
 
-node_io.room_for_item = function(pos, node, side, itemstack)
+node_io.room_for_item = function(pos, node, side, itemstack, count) -- returns non-negative number
 	local ndef = minetest.registered_nodes[node.name]
-	if not ndef.node_io_room_for_item then return false end
-	return ndef.node_io_room_for_item(pos, node, side, itemstack)
+	if not ndef.node_io_room_for_item then return 0 end
+	return ndef.node_io_room_for_item(pos, node, side, itemstack, count)
 end
-node_io.room_for_liquid = function(pos, node, side, liquid, millibuckets)
+node_io.room_for_liquid = function(pos, node, side, liquid, millibuckets) -- returns non-negative number
 	local ndef = minetest.registered_nodes[node.name]
-	if not ndef.node_io_room_for_liquid then return false end
+	if not ndef.node_io_room_for_liquid then return 0 end
 	return ndef.node_io_room_for_liquid(pos, node, side, liquid, millibuckets)
 end
 
@@ -130,6 +130,31 @@ node_io.make_itemstack = function(stack, count)
 	return itemstack
 end
 
+node_io.compare_itemstack = function(itemstack1, itemstack2)
+	if itemstack1:get_name() ~= itemstack2:get_name() then return false end
+	if itemstack1:get_wear() ~= itemstack2:get_wear() then return false end
+	if itemstack1:get_metadata() ~= itemstack2:get_metadata() then return false end
+	return true
+end
+
+node_io.room_for_item_in_inventory = function(inv, inv_name, itemstack, count)
+	local max = itemstack:get_stack_max()
+	local put_count = max
+	if count < put_count then put_count = count end
+	local room = 0
+	for i = 1, inv:get_size(inv_name) do
+		local stack = inv:get_stack("main", i)
+		if stack:is_empty() then return put_count end
+		if node_io.compare_itemstack(stack, itemstack) then
+			if stack:get_count() < max then
+				local room = room + max - stack:get_count()
+				if room >= put_count then return put_count end
+			end
+		end
+	end
+	return room
+end
+
 node_io.get_inventory_size = function(pos, inv_name)
 	local inv = minetest.get_meta(pos):get_inventory()
 	if not inv then return 0 end
@@ -196,10 +221,10 @@ node_io.init_main_inventory = function(node_name, allow_take)
 	local def = {}
 
 	def.node_io_can_put_item = function(pos, node, side) return true end
-	def.node_io_room_for_item = function(pos, node, side, itemstack)
+	def.node_io_room_for_item = function(pos, node, side, itemstack, count)
 		local inv = minetest.get_meta(pos):get_inventory()
-		if not inv then return false end
-		return inv:room_for_item("main", itemstack)
+		if not inv then return 0 end
+		return node_io.room_for_item_in_inventory(inv, "main", itemstack, count)
 	end
 	def.node_io_put_item = function(pos, node, side, putter, itemstack)
 		return node_io.put_item_in_inventory(pos, node, "main", putter, itemstack)

patches/hopper-tenplus1.patch

@@ -169,7 +169,7 @@ index 062c739..3fadaee 100644
 +			for i = 1, inv:get_size("main") do
 +				local stack = inv:get_stack("main", i)
 +				local item = stack:get_name()
-+				if item ~= "" and node_io.room_for_item(put_pos, put_node, put_side, node_io.make_itemstack(stack, 1)) then
++				if item ~= "" and node_io.room_for_item(put_pos, put_node, put_side, stack, 1) > 0 then
 +					node_io.put_item(put_pos, put_node, put_side, nil, stack:take_item(1))
 +					inv:set_stack("main", i, stack)
 +					minetest.get_node_timer(put_pos):start(0.5)