Always return the ItemStack for on_rightclick and on_place to comply with the api.

cooking.lua

@@ -52,7 +52,7 @@ function cauldron.filling(pos, node, clicker, itemstack)
 				else
 					minetest.chat_send_player(clicker:get_player_name(),
 						"No room in your inventory to add a bucket of water.")
-					return
+					return itemstack
 				end
 			else
 				itemstack:replace("bucket:bucket_water")
@@ -128,15 +128,15 @@ function cauldron.take_soup(pos, node, clicker, itemstack)
 			else
 				minetest.chat_send_player(clicker:get_player_name(),
 					"No room in your inventory to add a bowl of soup.")
-				return
+				return itemstack
 			end
 		else
 			itemstack:replace("xdecor:bowl_soup 1")
 		end
 
 		minetest.set_node(pos, {name="xdecor:cauldron_empty", param2=node.param2})
-		return itemstack
 	end
+	return itemstack
 end
 
 xdecor.register("cauldron_empty", {

itemframe.lua

@@ -71,7 +71,9 @@ function itemframe.rightclick(pos, node, clicker, itemstack)
 	local meta = minetest.get_meta(pos)
 	local player = clicker:get_player_name()
 	local owner = meta:get_string("owner")
-	if player ~= owner or not itemstack then return end
+	if player ~= owner or not itemstack then
+		return itemstack
+	end
 
 	drop_item(pos, node)
 	local itemstring = itemstack:take_item():to_string()

mailbox.lua

@@ -96,7 +96,7 @@ function mailbox.after_place_node(pos, placer)
 	inv:set_size("drop", 1)
 end
 
-function mailbox.rightclick(pos, _, clicker)
+function mailbox.rightclick(pos, node, clicker, itemstack, pointed_thing)
 	local meta = minetest.get_meta(pos)
 	local player = clicker:get_player_name()
 	local owner = meta:get_string("owner")
@@ -106,6 +106,7 @@ function mailbox.rightclick(pos, _, clicker)
 	else
 		minetest.show_formspec(player, "xdecor:mailbox", mailbox:formspec(pos, owner, 0))
 	end
+	return itemstack
 end
 
 function mailbox.put(pos, listname, _, stack, player)

mechanisms.lua

@@ -92,8 +92,10 @@ xdecor.register("lever_off", {
 	sounds = default.node_sound_stone_defaults(),
 	sunlight_propagates = true,
 	on_rotate = screwdriver.rotate_simple,
-	on_rightclick = function(pos, node, clicker)
+	on_rightclick = function(pos, node, clicker, itemstack, pointed_thing)
-		if not doors.get then return end
+		if not doors.get then
+			return itemstack
+		end
 		local minp = {x=pos.x-2, y=pos.y-1, z=pos.z-2}
 		local maxp = {x=pos.x+2, y=pos.y+1, z=pos.z+2}
 		local doors = minetest.find_nodes_in_area(minp, maxp, "group:door")
@@ -101,6 +103,7 @@ xdecor.register("lever_off", {
 		for i = 1, #doors do
 			door_toggle(pos, doors[i], clicker)
 		end
+		return itemstack
 	end
 })
 

nodes.lua

@@ -141,9 +141,10 @@ xdecor.register("chair", {
 		{11, 0,  3,   2,  6, 2}, {3,  6,  3, 10, 2, 8}
 	}),
 	can_dig = xdecor.sit_dig,
-	on_rightclick = function(pos, node, clicker, _, pointed_thing)
+	on_rightclick = function(pos, node, clicker, itemstack, pointed_thing)
 		pos.y = pos.y + 0  -- Sitting position.
 		xdecor.sit(pos, node, clicker, pointed_thing)
+		return itemstack
 	end
 })
 
@@ -175,8 +176,9 @@ for _, c in pairs({"red"}) do  -- Add more curtains colors simply here.
 		paramtype2 = "wallmounted",
 		groups = {dig_immediate=3, flammable=3},
 		selection_box = {type="wallmounted"},
-		on_rightclick = function(pos, node)
+		on_rightclick = function(pos, node, clicker, itemstack, pointed_thing)
 			minetest.set_node(pos, {name="xdecor:curtain_open_"..c, param2=node.param2})
+			return itemstack
 		end
 	})
 
@@ -188,8 +190,9 @@ for _, c in pairs({"red"}) do  -- Add more curtains colors simply here.
 		groups = {dig_immediate=3, flammable=3, not_in_creative_inventory=1},
 		selection_box = {type="wallmounted"},
 		drop = "xdecor:curtain_"..c,
-		on_rightclick = function(pos, node)
+		on_rightclick = function(pos, node, clicker, itemstack, pointed_thing)
 			minetest.set_node(pos, {name="xdecor:curtain_"..c, param2=node.param2})
+			return itemstack
 		end
 	})
 
@@ -207,9 +210,10 @@ xdecor.register("cushion", {
 	on_place = minetest.rotate_node,
 	node_box = xdecor.nodebox.slab_y(0.5),
 	can_dig = xdecor.sit_dig,
-	on_rightclick = function(pos, node, clicker, _, pointed_thing)
+	on_rightclick = function(pos, node, clicker, itemstack, pointed_thing)
 		pos.y = pos.y + 0  -- Sitting position.
 		xdecor.sit(pos, node, clicker, pointed_thing)
+		return itemstack
 	end
 })
 
@@ -372,8 +376,8 @@ xdecor.register("painting_1", {
 		end
 		if not minetest.setting_getbool("creative_mode") then
 			itemstack:take_item()
-			return itemstack
 		end
+		return itemstack
 	end
 })
 

rope.lua

@@ -12,7 +12,9 @@ function rope.place(itemstack, placer, pointed_thing)
 		local pos = pointed_thing.above
 		local oldnode = minetest.get_node(pos)
 		local stackname = itemstack:get_name()
-		if minetest.is_protected(pos, placer:get_player_name()) then return end
+		if minetest.is_protected(pos, placer:get_player_name()) then
+			return itemstack
+		end
 
 		while oldnode.name == "air" and not itemstack:is_empty() do
 			local newnode = {name = stackname, param1 = 0}