diff --git a/mods/ITEMS/mcl_buckets/init.lua b/mods/ITEMS/mcl_buckets/init.lua
index 56dd59ff9..648b9ef3c 100644
--- a/mods/ITEMS/mcl_buckets/init.lua
+++ b/mods/ITEMS/mcl_buckets/init.lua
@@ -90,47 +90,52 @@ function mcl_buckets.register_liquid(def)
 				else
 					node_place = def.source_place
 				end
-				-- Check if pointing to a buildable node
-				--local item = itemstack:get_name()
 
-				local mcl_into_cauldron = def._mcl_into_cauldron
+				local handle_fill_cauldron = def._mcl_get_bucket_from_cauldron
+				local skip_build = false
 
-				if mcl_into_cauldron then
-					local new_bucketname = mcl_into_cauldron(place_pos, user)
+				if handle_fill_cauldron then
+					local new_bucketname = handle_fill_cauldron(place_pos, user)
 					if not new_bucketname then
-						mcl_into_cauldron = nil
+						-- revoke cauldron codepath.
+						-- fall back to placing node normally.
+						handle_fill_cauldron = nil
+					else
+						skip_build = true
 					end
 				end
-				if def.extra_check and def.extra_check(place_pos, user) == true and nodedef and nodedef.buildable_to then
-					-- buildable; replace the node
-					local pns = user:get_player_name()
-					if minetest.is_protected(place_pos, pns) then
-						minetest.record_protection_violation(place_pos, pns)
-						return itemstack
-					end
-					place_liquid(place_pos, node_place)
-					if mod_doc and doc.entry_exists("nodes", node_place) then
-						doc.mark_entry_as_revealed(user:get_player_name(), "nodes", node_place)
-					end
-				elseif mcl_into_cauldron then
-					-- already handled; skip default case, to inventory handling.
-				else
-					-- not buildable to; place the liquid above
-					-- check if the node above can be replaced
-					local abovenode = minetest.get_node(pointed_thing.above)
-					if minetest.registered_nodes[abovenode.name] and minetest.registered_nodes[abovenode.name].buildable_to then
-						local pn = user:get_player_name()
-						if minetest.is_protected(pointed_thing.above, pn) then
-							minetest.record_protection_violation(pointed_thing.above, pn)
+				-- Check if pointing to a buildable node
+				--local item = itemstack:get_name()
+				if not skip_build then
+					if def.extra_check and def.extra_check(place_pos, user) == true and nodedef and nodedef.buildable_to then
+						-- buildable; replace the node
+						local pns = user:get_player_name()
+						if minetest.is_protected(place_pos, pns) then
+							minetest.record_protection_violation(place_pos, pns)
 							return itemstack
 						end
-						place_liquid(pointed_thing.above, node_place)
+						place_liquid(place_pos, node_place)
 						if mod_doc and doc.entry_exists("nodes", node_place) then
 							doc.mark_entry_as_revealed(user:get_player_name(), "nodes", node_place)
 						end
 					else
-						-- do not remove the bucket with the liquid
-						return
+						-- not buildable to; place the liquid above
+						-- check if the node above can be replaced
+						local abovenode = minetest.get_node(pointed_thing.above)
+						if minetest.registered_nodes[abovenode.name] and minetest.registered_nodes[abovenode.name].buildable_to then
+							local pn = user:get_player_name()
+							if minetest.is_protected(pointed_thing.above, pn) then
+								minetest.record_protection_violation(pointed_thing.above, pn)
+								return itemstack
+							end
+							place_liquid(pointed_thing.above, node_place)
+							if mod_doc and doc.entry_exists("nodes", node_place) then
+								doc.mark_entry_as_revealed(user:get_player_name(), "nodes", node_place)
+							end
+						else
+							-- do not remove the bucket with the liquid
+							return
+						end
 					end
 				end
 
@@ -237,29 +242,22 @@ minetest.register_craftitem("mcl_buckets:bucket_empty", {
 			end
 
 		elseif cauldron_stuff then
-		-- Cauldron
---[[
-		elseif minetest.get_item_group(nn, "cauldron") then
-			new_bucket = mcl_cauldrons.take_cauldron(pointed_thing.under, new_bucket, user)
---]]
+			-- Cauldron
 			local newnode
-			newnode = mcl_cauldrons.drain_levels(node, mcl_cauldrons.BUCKETFUL, "cauldron_water")
-			if node ~= newnode then
-				-- take water.
-				minetest.set_node(pointed_thing.under, newnode)
-				if not minetest.is_creative_enabled(user:get_player_name()) then
-					new_bucket = ItemStack({name = "mcl_buckets:bucket_water"})
-				end
-				sound_take("mcl_core:water_source", pointed_thing.under)
-			else
-				newnode = mcl_cauldrons.drain_levels(node, mcl_cauldrons.BUCKETFUL, "cauldron_river_water")
+			local CAULDRON_TO_BUCKET = {
+				["cauldron_water"]={bucket="mcl_buckets:bucket_water", sound="mcl_core:water_source"},
+				["cauldron_river_water"]={bucket="mcl_buckets:bucket_river_water", sound="mcl_core:river_water_source"},
+			}
+			for cauldron_specifier, bucket_spec in pairs(CAULDRON_TO_BUCKET) do
+				newnode = mcl_cauldrons.drain_levels(node, mcl_cauldrons.BUCKETFUL, cauldron_specifier)
 				if node ~= newnode then
-					-- take river water.
+					-- substance was taken out.
 					minetest.set_node(pointed_thing.under, newnode)
+					sound_take(bucket_spec.sound, pointed_thing.under)
 					if not minetest.is_creative_enabled(user:get_player_name()) then
-						new_bucket = ItemStack({name = "mcl_buckets:bucket_river_water"})
+						new_bucket = ItemStack({name = bucket_spec.bucket})
 					end
-					sound_take("mcl_core:river_water_source", pointed_thing.under)
+					break
 				end
 			end
 		end
diff --git a/mods/ITEMS/mcl_buckets/register.lua b/mods/ITEMS/mcl_buckets/register.lua
index 7c42fe4b4..e69785ba5 100644
--- a/mods/ITEMS/mcl_buckets/register.lua
+++ b/mods/ITEMS/mcl_buckets/register.lua
@@ -63,27 +63,15 @@ if mod_mcl_core then
 				return false
 			end
 			local nn = minetest.get_node(pos).name
-			-- Pour water into cauldron
-			if minetest.get_item_group(nn, "cauldron") ~= 0 then
---[[
-				-- Put water into cauldron
-				if nn ~= "mcl_cauldrons:cauldron_3" then
-					mcl_cauldrons.set_cauldron_level(pos, "water", 3)
-				end
-				sound_place("mcl_core:water_source", pos)
-				return false
---]]
 			-- Evaporate water if used in Nether (except on cauldron)
-			else
-				local dim = mcl_worlds.pos_to_dimension(pos)
-				if dim == "nether" then
-					minetest.sound_play("fire_extinguish_flame", {pos = pos, gain = 0.25, max_hear_distance = 16}, true)
-					return false
-				end
+			local dim = mcl_worlds.pos_to_dimension(pos)
+			if dim == "nether" then
+				minetest.sound_play("fire_extinguish_flame", {pos = pos, gain = 0.25, max_hear_distance = 16}, true)
+				return false
 			end
 		end,
 		groups = { water_bucket = 1 },
-		_mcl_into_cauldron = function (pos, placer)
+		_mcl_get_bucket_from_cauldron = function(pos, placer)
 			local node = minetest.get_node(pos)
 			if not mcl_cauldrons.is_cauldron(node) then
 				return nil
@@ -129,27 +117,15 @@ if mod_mclx_core then
 				return false
 			end
 			local nn = minetest.get_node(pos).name
-			-- Pour into cauldron
-			if minetest.get_item_group(nn, "cauldron") ~= 0 then
---[[
-				-- Put water into cauldron
-				if nn ~= "mcl_cauldrons:cauldron_3r" then
-					mcl_cauldrons.set_cauldron(pos, "river_water", 3)
-				end
-				sound_place("mcl_core:water_source", pos)
+			-- Evaporate water if used in Nether (except on cauldron)
+			local dim = mcl_worlds.pos_to_dimension(pos)
+			if dim == "nether" then
+				minetest.sound_play("fire_extinguish_flame", {pos = pos, gain = 0.25, max_hear_distance = 16}, true)
 				return false
---]]
-			else
-				-- Evaporate water if used in Nether (except on cauldron)
-				local dim = mcl_worlds.pos_to_dimension(pos)
-				if dim == "nether" then
-					minetest.sound_play("fire_extinguish_flame", {pos = pos, gain = 0.25, max_hear_distance = 16}, true)
-					return false
-				end
 			end
 		end,
 		groups = { water_bucket = 1 },
-		_mcl_into_cauldron = function (pos, placer)
+		_mcl_get_bucket_from_cauldron = function(pos, placer)
 			local node = minetest.get_node(pos)
 			if not mcl_cauldrons.is_cauldron(node) then
 				return nil
diff --git a/mods/ITEMS/mcl_cauldrons/API.md b/mods/ITEMS/mcl_cauldrons/API.md
index 381d43d06..768815dcb 100644
--- a/mods/ITEMS/mcl_cauldrons/API.md
+++ b/mods/ITEMS/mcl_cauldrons/API.md
@@ -1,33 +1,7 @@
-# mcl_cauldrons
+# `mcl_cauldrons`
 
 This mod add an API to add cauldrons to mcl.
 
-## mcl_cauldrons.is_cauldron(name)
-return true if name is cauldron, false overwise.
-
-## mcl_cauldrons.get_cauldron_string(type, level)
-return itemstring of cauldron with <type> and <level>
-e.g: `mcl_cauldrons.get_cauldron_string("water", 1) --return itemstring of a water cauldron with 1 level of water`
-
-## mcl_cauldrons.take_cauldron(pos, itemstack, user, sounds)
-empty cauldron at `pos`
-return `bucket` field of the cauldron def if user is player, itemstack overwise.
-* pos: position of the cauldron
-* itemstack: will be return if `bucket` field isn't defined in cauldron def or user is nil or not player.
-* user: player who takes cauldron
-* sounds: sounds table. If not nil, dug sound will be played.
-
-## mcl_cauldrons.register_cauldron_type(def)
-def can have these fields:
-* name: name of the liquid e.g: "water"
-* bucket: string of the bucket item. can be nil. e.g: "mcl_buckets:bucket_water"
-* desc: description of the item. %s will be replaced by the level. e.g: "Water Cauldron %s/3 full"
-* texture: texture of the flowing liquid e.g: "mcl_core_water_flowing.png"
-
-## `mcl_cauldrons.registered_cauldrons`
-Table containing cauldron definitions, indexed by name.
-
-
 
 Node definitions
 ----------------
@@ -44,8 +18,10 @@ Extensions to the base node definition descriptor (as passed to `minetest.regist
 * `.mcl_on_drain(node, amount)`: returns node { name, param1, param2 }
 
 
-### `mcl_cauldrons.register_cauldron_node(nodename, cauldron_def)`
+### `mcl_cauldrons.registered_cauldrons`
+Table containing cauldron definitions, indexed by name.
 
+### `mcl_cauldrons.register_cauldron_node(nodename, cauldron_def)`
 
 
 Cauldron interactions
diff --git a/mods/ITEMS/mcl_cauldrons/api.lua b/mods/ITEMS/mcl_cauldrons/api.lua
index 5d6dcab86..79f24160a 100644
--- a/mods/ITEMS/mcl_cauldrons/api.lua
+++ b/mods/ITEMS/mcl_cauldrons/api.lua
@@ -1,186 +1,27 @@
 local has_doc = minetest.get_modpath(minetest.get_current_modname())
 
---[[
-local function survival_give(inv, original_item, itemstack)
-    if inv:room_for_item("main", itemstack) then
-        inv:add_item("main", itemstack)
-        return original_item:take_item()
-    else
-        minetest.add_item(user:get_pos(), itemstack)
-        return original_item
-    end
-end
-
-local function creative_give(inv, original_item, itemstack)
-    if not inv:contains_item("main", itemstack) then
-        inv:add_item("main", itemstack)
-        return original_item
-    end
-end
-
-local function give_item(user, original_item, itemstack)
-	local inv = user:get_inventory()
-	if inv then
-		if minetest.is_creative_enabled(user:get_player_name()) then
-            creative_give(inv, original_item, itemstack)
-        else
-            survival_give(inv, original_item, itemstack)
-        end
-	end
-	return itemstack
-end
-
---]]
 mcl_cauldrons.registered_cauldrons = {}
---[[
-
-function mcl_cauldrons.register_cauldron_type(def)
-	for water_level = 1,3 do
-		local id = "mcl_cauldrons:cauldron_"..def.name.."_"..water_level
-		mcl_cauldrons.registered_cauldrons[id] = def
-		minetest.register_node(id, {
-			description = string.format(def.desc, water_level),
-			_doc_items_create_entry = false,
-			use_texture_alpha = minetest.features.use_texture_alpha_string_modes and "opaque" or false,
-			drawtype = "nodebox",
-			paramtype = "light",
-			is_ground_content = false,
-			groups = {pickaxey=1, not_in_creative_inventory=1, cauldron=(1+water_level), cauldron_filled=water_level, comparator_signal=water_level},
-			node_box = mcl_cauldrons.cauldron_nodeboxes[water_level],
-			collision_box = mcl_cauldrons.cauldron_nodeboxes[0],
-			selection_box = { type = "regular" },
-			tiles = {
-				"("..def.texture.."^[verticalframe:16:0"..")^mcl_cauldrons_cauldron_top.png",
-				"mcl_cauldrons_cauldron_inner.png^mcl_cauldrons_cauldron_bottom.png",
-				"mcl_cauldrons_cauldron_side.png"
-			},
-			sounds = mcl_sounds.node_sound_metal_defaults(),
-			drop = "mcl_cauldrons:cauldron",
-			_mcl_hardness = 2,
-			_mcl_blast_resistance = 2,
-		})
-		-- Add entry aliases for the Help
-		if has_doc then
-			doc.add_entry_alias("nodes", "mcl_cauldrons:cauldron", "nodes", id)
-		end
-	end
-end
-
-function mcl_cauldrons.is_cauldron(name)
-	return minetest.get_item_group(name, "cauldron") ~= 0
-end
-
--------------------------------------
---Functions to get/set cauldron level
--------------------------------------
-function mcl_cauldrons.get_cauldron_level(pos)
-	local nn = minetest.get_node(pos)
-	return minetest.get_item_group(nn.name, "cauldron")
-end
-
-function mcl_cauldrons.set_cauldron_level(pos, type, level)
-	return minetest.set_node(pos, {name = mcl_cauldrons.get_cauldron_string(type, level)})
-end
-
-function mcl_cauldrons.add_cauldron_level(pos, type, number)
-	local current = mcl_cauldrons.get_cauldron_level(pos)
-	local number = current + number
-	if number > 4 then number = 4 end
-	if number < 1 then number = 1 end
-	mcl_cauldrons.set_cauldron_level(pos, type, number)
-	return number, not current == number
-end
-
-function mcl_cauldrons.get_cauldron_string(type, level)
-	if mcl_cauldrons.registered_cauldrons["mcl_cauldrons:cauldron_"..type.."_"..level] then
-		return "mcl_cauldrons:cauldron_"..type.."_"..level
-	elseif level == 0 then
-		return "mcl_cauldrons:cauldron"
-	else
-		minetest.log("warning", "[mcl_cauldrons] trying to get string from invalid cauldron params")
-		return "air"
-	end
-end
-
-----------------------------
---Functions to take cauldron
-----------------------------
-function mcl_cauldrons.take_cauldron(pos, itemstack, user, sounds)
-	local nn = minetest.get_node(pos)
-	if mcl_cauldrons.registered_cauldrons[nn.name] and mcl_cauldrons.registered_cauldrons[nn.name].bucket then
-		if user and not minetest.is_creative_enabled(user:get_player_name()) then
-			minetest.set_node(pos, {name="mcl_cauldrons:cauldron"})
-			if sounds then minetest.sound_play(sounds.dug, {gain=1.0, pos = pos, pitch = 1 + math.random(-10, 10)*0.005}, true) end
-			return give_item(user, original, ItemStack(mcl_cauldrons.registered_cauldrons[nn.name].bucket))
-		else
-			minetest.set_node(pos, {name="mcl_cauldrons:cauldron"})
-			if sounds then minetest.sound_play(sounds.dug, {gain=1.0, pos = pos, pitch = 1 + math.random(-10, 10)*0.005}, true) end
-			return itemstack
-		end
-	else
-		minetest.set_node(pos, {name="mcl_cauldrons:cauldron"})
-		if sounds then minetest.sound_play(sounds.dug, {gain=1.0, pos = pos, pitch = 1 + math.random(-10, 10)*0.005}, true) end
-		return itemstack
-	end
-end
-
-function mcl_cauldrons.take_small_cauldron(pos, itemstack, user, sounds)
-	local nn = minetest.get_node(pos)
-	if mcl_cauldrons.registered_cauldrons[nn.name] and mcl_cauldrons.registered_cauldrons[nn.name].bottle then
-		if user and not minetest.is_creative_enabled(user:get_player_name()) then
-			local number, changed = mcl_cauldrons.add_cauldron_level(pos, mcl_cauldrons.registered_cauldrons[nn.name].name, -1)
-			if changed then
-				if sounds then minetest.sound_play(sounds.dug, {gain=1.0, pos = pos, pitch = 1 + math.random(-10, 10)*0.005}, true) end
-				local item_name = mcl_cauldrons.registered_cauldrons[nn.name].bottle
-				local inv = placer:get_inventory()
-				minetest.sound_play("mcl_potions_bottle_fill", {pos=pointed_thing.under, gain=0.5, max_hear_range=16}, true)
-				if minetest.is_creative_enabled(placer:get_player_name()) then
-					-- Don't replace empty bottle in creative for convenience reasons
-					if not inv:contains_item("main", item_name) then
-						inv:add_item("main", item_name)
-					end
-				elseif itemstack:get_count() == 1 then
-					return item_name
-				else
-					return give_item(user, ItemStack(mcl_cauldrons.registered_cauldrons[nn.name].bucket))
-				end
-			end
-		else
-			local number = mcl_cauldrons.add_cauldron_level(pos, mcl_cauldrons.registered_cauldrons[nn.name].name, -1)
-			if number ~= 0 then
-				if sounds then minetest.sound_play(sounds.dug, {gain=1.0, pos = pos, pitch = 1 + math.random(-10, 10)*0.005}, true) end
-			end
-			return itemstack
-		end
-	else
-		local number = mcl_cauldrons.add_cauldron_level(pos, mcl_cauldrons.registered_cauldrons[nn.name].name, -1)
-		if number ~= 0 then
-			if sounds then minetest.sound_play(sounds.dug, {gain=1.0, pos = pos, pitch = 1 + math.random(-10, 10)*0.005}, true) end
-		end
-		return itemstack
-	end
-end
-
---]]
-
-
-
-
-
-
-----------------------------------------
 
 
+-- symbolic constants.
 mcl_cauldrons.BUCKETFUL = 3
 mcl_cauldrons.BOTTLEFUL = 1
 
 
+-- Find cauldron from registered cauldrons -> string, table
+--  `substance` == nil for any cauldron content (incl. empty), "" = only empty.
+--  `fill_level` == nil for any/first fill level satisfying `substance`.
+-- e.g. find_cauldron("cauldron_water", 2) -> "mcl_cauldrons:cauldron_water_2"
+-- Returns 2 values: node_name:string, node_definition:table;
+-- if nothing else matches, returns empty cauldron ("mcl_cauldrons:cauldron").
 function mcl_cauldrons.find_cauldron (substance, fill_level)
 	if (substance == "") then
 		fill_level = 0
 	end
 	for nodename, nodedef in pairs(mcl_cauldrons.registered_cauldrons) do
+		-- matched on substance: 'any', or exact match from .groups.
 		local substantial = (substance == nil) or (nodedef.groups[substance] and (nodedef.groups[substance] > 0))
+		-- matched on fill_level: 'any', or exact match from .groups.
 		local filling = (fill_level == nil) or (nodedef.groups.cauldron_filled == fill_level)
 		if substantial and filling then
 			return nodename, nodedef
@@ -191,14 +32,19 @@ function mcl_cauldrons.find_cauldron (substance, fill_level)
 	return nodename, mcl_cauldrons.registered_cauldrons[nodename]
 end
 
+-- Test: node describes a cauldron -> boolean
 function mcl_cauldrons.is_cauldron (node)
-	return (minetest.get_item_group(node.name, "cauldron"))
+	return (minetest.get_item_group(node.name, "cauldron") > 0)
 end
 
+-- Test: cauldron node contains specified substance -> boolean
 function mcl_cauldrons.has_substance (node, substance)
 	return (minetest.get_item_group(node.name, substance) > 0)
 end
 
+-- Get maximum number of levels available for cauldron node -> number
+-- Optionally specify `substance` (mainly to determine a change in cauldron substance, e.g. filling a full one with bucket of something else)
+-- substance == nil to ignore substance criteria
 function mcl_cauldrons.get_maximum (node, substance)
 	local nodename
 	if substance == nil then
@@ -209,6 +55,8 @@ function mcl_cauldrons.get_maximum (node, substance)
 	return minetest.get_item_group(nodename, "cauldron_maximum")
 end
 
+-- Get current level of cauldron -> number
+-- Optionally specify `substance`, substance==nil to indicate current content.
 function mcl_cauldrons.get_level (node, substance)
 	if substance and (minetest.get_item_group(node.name, substance) == 0) then
 		return 0
@@ -216,6 +64,8 @@ function mcl_cauldrons.get_level (node, substance)
 	return minetest.get_item_group(node.name, "cauldron_filled")
 end
 
+-- Test: cauldron is empty -> boolean
+-- (i.e. fill level is 0, or contents is empty)
 function mcl_cauldrons.is_empty (node)
 	if not mcl_cauldrons.is_cauldron(node) then
 		error("not a cauldron", node.name)
@@ -226,18 +76,26 @@ function mcl_cauldrons.is_empty (node)
 	return false
 end
 
+-- Test: cauldron is full -> boolean
+-- (i.e. current fill level matches maximum level.
 function mcl_cauldrons.is_full (node)
 	local maximum = mcl_cauldrons.get_maximum(node)
 	local current = mcl_cauldrons.get_level(node)
 	return (current >= maximum)
 end
 
+-- Set fill level, bypassing game rules -> table
+-- Optionally indicate substance (to change cauldron content); nil to preserve.
+-- returns a node table as accepted by minetest.set_node()
 function mcl_cauldrons.set_level (node, fill_level, substance)
 	local nodename, nodedef = mcl_cauldrons.find_cauldron(substance, fill_level)
 	local newnode = { name = nodename, param1 = node.param1, param2 = node.param2 }
 	return newnode
 end
 
+-- Change content of cauldron by number of levels with indicated substance -> table
+-- Subject to game rules (delegated to node definition's on_fill callback)
+-- returns a node table as accepted by minetest.set_node()
 function mcl_cauldrons.fill_levels (node, change_levels, substance)
 	local nodedef = mcl_cauldrons.registered_cauldrons[node.name]
 	local callback = nodedef.mcl_on_fill
@@ -253,6 +111,7 @@ function mcl_cauldrons.fill_levels (node, change_levels, substance)
 	return newnode
 end
 
+-- drain counterpart to fill_levels()
 function mcl_cauldrons.drain_levels (node, change_levels, substance)
 	local nodedef = mcl_cauldrons.registered_cauldrons[node.name]
 	local callback = nodedef.mcl_on_drain
@@ -269,6 +128,8 @@ function mcl_cauldrons.drain_levels (node, change_levels, substance)
 end
 
 
+-- Wrapper to register cauldron-specific nodes.
+-- additional bookkeeping specific to mcl_cauldrons.
 function mcl_cauldrons.register_cauldron_node (nodename, nodedef, doc_alias)
 	mcl_cauldrons.registered_cauldrons[nodename] = nodedef
 	minetest.register_node(nodename, nodedef)
diff --git a/mods/ITEMS/mcl_cauldrons/init.lua b/mods/ITEMS/mcl_cauldrons/init.lua
index 75258bfcf..0d073b0cc 100644
--- a/mods/ITEMS/mcl_cauldrons/init.lua
+++ b/mods/ITEMS/mcl_cauldrons/init.lua
@@ -4,6 +4,5 @@ local modpath = minetest.get_modpath(minetest.get_current_modname())
 mcl_cauldrons = {}
 -- Cauldron mod, adds cauldrons.
 
-dofile(modpath.."/utils.lua")
 dofile(modpath.."/api.lua")
 dofile(modpath.."/register.lua")
diff --git a/mods/ITEMS/mcl_cauldrons/register.lua b/mods/ITEMS/mcl_cauldrons/register.lua
index 29a048a76..0c1198bfe 100644
--- a/mods/ITEMS/mcl_cauldrons/register.lua
+++ b/mods/ITEMS/mcl_cauldrons/register.lua
@@ -33,12 +33,18 @@ local create_cauldron_nodebox = function(water_level)
 	}
 end
 
+-- Generate nodeboxes for cauldrons, (0=empty, 1=1/3 filled, 2=2/3 filled, 3=full)
 mcl_cauldrons.cauldron_nodeboxes = {}
 for w=0,3 do
 	mcl_cauldrons.cauldron_nodeboxes[w] = create_cauldron_nodebox(w)
 end
 
 
+-- The normal Lua means of inheritance uses setmetatable.
+-- For node definitions, minetest.register_node() breaks/overwrite the metatable for its own use.
+-- This function copies in the "old" keys/values, to lets them be overwritten by another (newer) table.
+-- Care should be exercised updating/modifying the return value, as nested tables are copied by reference (viz. followup code might end up modifying nested tables in the *parent* defintion).
+-- This workaround happens to work as declarative objects do not change after instantiation.
 local function merge_tables (a,b)
 	local result = {}
 	for k,v in pairs(a) do result[k]=v end
@@ -71,7 +77,7 @@ mcl_cauldrons.register_cauldron_node("mcl_cauldrons:cauldron", {
 	_mcl_hardness = 2,
 	_mcl_blast_resistance = 2,
 
-	mcl_on_fill = function (node, change_levels, substance)
+	mcl_on_fill = function(node, change_levels, substance)
 		-- base rules for cauldrons.
 		if change_levels <= 0 then
 			-- no change.
@@ -97,7 +103,7 @@ mcl_cauldrons.register_cauldron_node("mcl_cauldrons:cauldron", {
 		local newnode = mcl_cauldrons.set_level(node, new_level, substance)
 		return newnode
 	end,
-	mcl_on_drain = function (node, change_levels, substance)
+	mcl_on_drain = function(node, change_levels, substance)
 		-- base rules for cauldrons.
 		if change_levels <= 0 then
 			-- no change.
@@ -128,15 +134,6 @@ mcl_cauldrons.register_cauldron_node("mcl_cauldrons:cauldron", {
 	end,
 })
 
---[[
-mcl_cauldrons.register_cauldron_type({
-	name = "water",
-	bucket = "mcl_buckets:bucket_water",
-	bottle = "mcl_potions:water",
-	desc = S("Cauldron (%s/3 Water)"),
-	texture = "default_water_source_animated.png"
-})
---]]
 
 -- water cauldron as extension of empty cauldron.
 mcl_cauldrons.register_cauldron_node("mcl_cauldrons:cauldron_water_1",
@@ -150,14 +147,14 @@ mcl_cauldrons.register_cauldron_node("mcl_cauldrons:cauldron_water_1",
 		cauldron_water = 1,
 		},
 	node_box = mcl_cauldrons.cauldron_nodeboxes[1],
-	collision_box = mcl_cauldrons.cauldron_nodeboxes[1],
+	collision_box = mcl_cauldrons.cauldron_nodeboxes[0],
 	tiles = {
 			"(default_water_source_animated.png^[verticalframe:16:0"..")^mcl_cauldrons_cauldron_top.png",
 			"mcl_cauldrons_cauldron_inner.png^mcl_cauldrons_cauldron_bottom.png",
 			"mcl_cauldrons_cauldron_side.png"
 	},
 	drop = "mcl_cauldrons:cauldron",
-}))
+}), "mcl_cauldrons:cauldron")
 
 -- water cauldron 2/3 as extension of 1/3.
 mcl_cauldrons.register_cauldron_node("mcl_cauldrons:cauldron_water_2",
@@ -171,8 +168,7 @@ mcl_cauldrons.register_cauldron_node("mcl_cauldrons:cauldron_water_2",
 		cauldron_water = 1,
 		},
 	node_box = mcl_cauldrons.cauldron_nodeboxes[2],
-	collision_box = mcl_cauldrons.cauldron_nodeboxes[2],
-}))
+}), "mcl_cauldrons:cauldron")
 
 -- water cauldron 3/3 as extension of 1/3.
 mcl_cauldrons.register_cauldron_node("mcl_cauldrons:cauldron_water_3",
@@ -186,8 +182,7 @@ mcl_cauldrons.register_cauldron_node("mcl_cauldrons:cauldron_water_3",
 		cauldron_water = 1,
 		},
 	node_box = mcl_cauldrons.cauldron_nodeboxes[3],
-	collision_box = mcl_cauldrons.cauldron_nodeboxes[3],
-}))
+}), "mcl_cauldrons:cauldron")
 
 if minetest.get_modpath("mclx_core") then
 	--register_filled_cauldron(1, S("Cauldron (1/3 River Water)"), true)
@@ -205,14 +200,14 @@ if minetest.get_modpath("mclx_core") then
 			cauldron_river_water = 1,
 			},
 		node_box = mcl_cauldrons.cauldron_nodeboxes[1],
-		collision_box = mcl_cauldrons.cauldron_nodeboxes[1],
+		collision_box = mcl_cauldrons.cauldron_nodeboxes[0],
 		tiles = {
 				"(default_river_water_source_animated.png^[verticalframe:16:0"..")^mcl_cauldrons_cauldron_top.png",
 				"mcl_cauldrons_cauldron_inner.png^mcl_cauldrons_cauldron_bottom.png",
 				"mcl_cauldrons_cauldron_side.png"
 		},
 		drop = "mcl_cauldrons:cauldron",
-	}))
+	}), "mcl_cauldrons:cauldron")
 	-- water cauldron 2/3 as extension of 1/3.
 	mcl_cauldrons.register_cauldron_node("mcl_cauldrons:cauldron_river_water_2",
 		merge_tables(mcl_cauldrons.registered_cauldrons["mcl_cauldrons:cauldron_river_water_1"], {
@@ -225,8 +220,7 @@ if minetest.get_modpath("mclx_core") then
 			cauldron_river_water = 1,
 			},
 		node_box = mcl_cauldrons.cauldron_nodeboxes[2],
-		collision_box = mcl_cauldrons.cauldron_nodeboxes[2],
-	}))
+	}), "mcl_cauldrons:cauldron")
 	-- water cauldron 3/3 as extension of 1/3.
 	mcl_cauldrons.register_cauldron_node("mcl_cauldrons:cauldron_river_water_3",
 		merge_tables(mcl_cauldrons.registered_cauldrons["mcl_cauldrons:cauldron_river_water_1"], {
@@ -239,10 +233,11 @@ if minetest.get_modpath("mclx_core") then
 			cauldron_river_water = 1,
 			},
 		node_box = mcl_cauldrons.cauldron_nodeboxes[3],
-		collision_box = mcl_cauldrons.cauldron_nodeboxes[3],
-	}))
+	}), "mcl_cauldrons:cauldron")
 end
 
+
+-- Crafting recipe: Cauldron
 minetest.register_craft({
 	output = "mcl_cauldrons:cauldron",
 	recipe = {
@@ -258,25 +253,21 @@ minetest.register_abm({
 	interval = 0.5,
 	chance = 1,
 	action = function(pos, node)
-		for _, obj in pairs(minetest.get_objects_inside_radius(pos, 0.4)) do
+		local EXTINGUISHING_RADIUS = 0.4
+		for _, obj in pairs(minetest.get_objects_inside_radius(pos, EXTINGUISHING_RADIUS)) do
 			if mcl_burning.is_burning(obj) then
-				mcl_burning.extinguish(obj)
-				local new_group = minetest.get_item_group(node.name, "cauldron_filled") - 1
-				minetest.swap_node(pos, {name = "mcl_cauldrons:cauldron" .. (new_group == 0 and "" or "_" .. new_group)})
-				break
+				local newnode = mcl_cauldrons.drain_levels(node, 1, "cauldron_water")
+				if node ~= newnode then
+					-- extinguishing requires 1 level of water from cauldron.
+					minetest.swap_node(pos, newnode)
+					mcl_burning.extinguish(obj)
+					break
+				end
 			end
 		end
 	end
 })
 
---[[
-for i = 1, 3 do --Backward compatibility
-	minetest.register_alias("mcl_cauldrons:cauldron_"..i, "mcl_cauldrons:cauldron_water_"..i)
-end
-for i = 1, 3 do
-	minetest.register_alias("mcl_cauldrons:cauldron_"..i.."r", "mcl_cauldrons:cauldron_river_water_"..i)
-end
---]]
 
 -- backwards compatibility
 local aliases = {
diff --git a/mods/ITEMS/mcl_cauldrons/utils.lua b/mods/ITEMS/mcl_cauldrons/utils.lua
deleted file mode 100644
index 313cb379c..000000000
--- a/mods/ITEMS/mcl_cauldrons/utils.lua
+++ /dev/null
@@ -1,65 +0,0 @@
-local S = minetest.get_translator(minetest.get_current_modname())
-
--- Convenience function because the cauldron nodeboxes are very similar
-local create_cauldron_nodebox = function(water_level)
-	local floor_y
-	if water_level == 0 then	-- empty
-		floor_y = -0.1875
-	elseif water_level == 1 then	-- 1/3 filled
-		floor_y = 1/16
-	elseif water_level == 2 then	-- 2/3 filled
-		floor_y = 4/16
-	elseif water_level == 3 then	-- full
-		floor_y = 7/16
-	end
-	return {
-		type = "fixed",
-		fixed = {
-			{-0.5, -0.1875, -0.5, -0.375, 0.5, 0.5}, -- Left wall
-			{0.375, -0.1875, -0.5, 0.5, 0.5, 0.5}, -- Right wall
-			{-0.375, -0.1875, 0.375, 0.375, 0.5, 0.5}, -- Back wall
-			{-0.375, -0.1875, -0.5, 0.375, 0.5, -0.375}, -- Front wall
-			{-0.5, -0.3125, -0.5, 0.5, floor_y, 0.5}, -- Floor
-			{-0.5, -0.5, -0.5, -0.375, -0.3125, -0.25}, -- Left front foot, part 1
-			{-0.375, -0.5, -0.5, -0.25, -0.3125, -0.375}, -- Left front foot, part 2
-			{-0.5, -0.5, 0.25, -0.375, -0.3125, 0.5}, -- Left back foot, part 1
-			{-0.375, -0.5, 0.375, -0.25, -0.3125, 0.5}, -- Left back foot, part 2
-			{0.375, -0.5, 0.25, 0.5, -0.3125, 0.5}, -- Right back foot, part 1
-			{0.25, -0.5, 0.375, 0.375, -0.3125, 0.5}, -- Right back foot, part 2
-			{0.375, -0.5, -0.5, 0.5, -0.3125, -0.25}, -- Right front foot, part 1
-			{0.25, -0.5, -0.5, 0.375, -0.3125, -0.375}, -- Right front foot, part 2
-		}
-	}
-end
-
-mcl_cauldrons.cauldron_nodeboxes = {}
-for w=0,3 do
-	mcl_cauldrons.cauldron_nodeboxes[w] = create_cauldron_nodebox(w)
-end
-
--- Empty cauldron
---[[
-minetest.register_node("mcl_cauldrons:cauldron", {
-	description = S("Cauldron"),
-	_tt_help = S("Stores water"),
-	_doc_items_longdesc = S("Cauldrons are used to store water and slowly fill up under rain."),
-	_doc_items_usagehelp = S("Place a water pucket into the cauldron to fill it with water. Place an empty bucket on a full cauldron to retrieve the water. Place a water bottle into the cauldron to fill the cauldron to one third with water. Place a glass bottle in a cauldron with water to retrieve one third of the water."),
-	wield_image = "mcl_cauldrons_cauldron.png",
-	inventory_image = "mcl_cauldrons_cauldron.png",
-	use_texture_alpha = minetest.features.use_texture_alpha_string_modes and "opaque" or false,
-	drawtype = "nodebox",
-	paramtype = "light",
-	is_ground_content = false,
-	groups = {pickaxey=1, deco_block=1, cauldron=1},
-	node_box = mcl_cauldrons.cauldron_nodeboxes[0],
-	selection_box = { type = "regular" },
-	tiles = {
-		"mcl_cauldrons_cauldron_inner.png^mcl_cauldrons_cauldron_top.png",
-		"mcl_cauldrons_cauldron_inner.png^mcl_cauldrons_cauldron_bottom.png",
-		"mcl_cauldrons_cauldron_side.png"
-	},
-	sounds = mcl_sounds.node_sound_metal_defaults(),
-	_mcl_hardness = 2,
-	_mcl_blast_resistance = 2,
-})
---]]
diff --git a/mods/ITEMS/mcl_potions/init.lua b/mods/ITEMS/mcl_potions/init.lua
index 650b6ea0f..495a484ec 100644
--- a/mods/ITEMS/mcl_potions/init.lua
+++ b/mods/ITEMS/mcl_potions/init.lua
@@ -41,6 +41,34 @@ minetest.register_craft({
 })
 
 
+local function deposit_player_inventory (placer, itemstack, item_name)
+	local new_itemstack = ItemStack({name=item_name})
+	local inv = placer:get_inventory()
+	if minetest.is_creative_enabled(placer:get_player_name()) then
+		-- creative mode: have at most one.
+		if not inv:contains_item("main", new_itemstack) then
+			inv:add_item("main", new_itemstack)
+		end
+	else
+		-- survival mode
+		if itemstack:get_count() <= 1 then
+			-- swap in place.
+			return new_itemstack
+		elseif inv:room_for_item("main", new_itemstack) then
+			-- add to inventory, take one.
+			itemstack:take_item()
+			inv:add_item("main", new_itemstack)
+			return itemstack
+		else
+			-- drop in place.
+			itemstack:take_item()
+			minetest.add_item(placer:get_pos(), item_name)
+		end
+	end
+	-- no change in inventory.
+	return itemstack
+end
+
 local function take_from_cauldron (pos, node, itemstack, placer)
 	local sounds = mcl_sounds.node_sound_metal_defaults() -- TODO: should come from declarative object
 	-- check cauldron limits.
@@ -56,30 +84,15 @@ local function take_from_cauldron (pos, node, itemstack, placer)
 		end
 	end
 	if new_bottlename then
-		-- byproduct of draining cauldron.
-		local new_bottle = ItemStack({name=new_bottlename})
-		local inv = placer:get_inventory()
-		if minetest.is_creative_enabled(placer:get_player_name()) then
-			-- creative mode: get for free
-			if not inv:contains_item("main", new_bottle) then
-				inv:add_item("main", new_bottle)
-			end
-		else
-			-- survival mode
-			if inv:room_for_item("main", new_bottle) then
-				itemstack:take_item()
-				inv:add_item("main", new_bottle)
-			else
-				minetest.add_item(placer:get_pos(), new_bottle)
-			end
-		end
-		return true
+		return deposit_player_inventory(placer, itemstack, new_bottlename)
 	end
+	-- no change in inventory.
+	return itemstack
 end
 
 local function give_to_cauldron (pos, node, itemstack, placer, substance)
 	if substance == nil then
-		return false
+		return itemstack
 	end
 	local sounds = mcl_sounds.node_sound_metal_defaults() -- TODO: should come from declarative object
 	-- check cauldron limits.
@@ -88,8 +101,7 @@ local function give_to_cauldron (pos, node, itemstack, placer, substance)
 	local level = mcl_cauldrons.get_level(node, substance)
 	local fit = maximum - level
 	if fit > 0 then
-		-- sufficiently low level, add.
-		-- overwrites old content (old contents are lost).
+		-- sufficiently low level, add; old contents are lost.
 		local newnode = mcl_cauldrons.fill_levels(node, mcl_cauldrons.BOTTLEFUL, substance)
 		if node ~= new_node then
 			-- change happened
@@ -99,25 +111,10 @@ local function give_to_cauldron (pos, node, itemstack, placer, substance)
 		end
 	end
 	if new_bottlename then
-		-- byproduct of filling cauldron.
-		local new_bottle = ItemStack({name=new_bottlename})
-		local inv = placer:get_inventory()
-		if minetest.is_creative_enabled(placer:get_player_name()) then
-			-- creative mode: get for free
-			if not inv:contains_item("main", new_bottle) then
-				inv:add_item("main", new_bottle)
-			end
-		else
-			-- survival mode
-			if inv:room_for_item("main", new_bottle) then
-				itemstack:take_item()
-				inv:add_item("main", new_bottle)
-			else
-				minetest.add_item(placer:get_pos(), new_bottle)
-			end
-		end
-		return true
+		return deposit_player_inventory(placer, itemstack, new_bottlename)
 	end
+	-- no change in inventory.
+	return itemstack
 end
 
 
@@ -155,16 +152,9 @@ minetest.register_craftitem("mcl_potions:glass_bottle", {
 				get_water = true
 				--from_liquid_source = true
 				river_water = node.name == "mclx_core:river_water_source"
+				local new_bottlename = river_water and "mcl_potions:river_water" or "mcl_potions:water"
+				return deposit_player_inventory(placer, itemstack, new_bottlename)
 			-- Or reduce water level of cauldron by 1
---[[
-			elseif mcl_cauldrons.is_cauldron(node.name) then
-				local pname = placer:get_player_name()
-				if minetest.is_protected(pointed_thing.under, pname) then
-					minetest.record_protection_violation(pointed_thing.under, pname)
-					return itemstack
-				end
-				mcl_cauldrons.take_small_cauldron(pointed_thing.under, itemstack, placer, {dug = "mcl_potions_bottle_fill"})
---]]
 			elseif from_cauldron then
 				if mcl_cauldrons.get_level(node, "cauldron_water") > 0 then
 					-- take bottle of water.
@@ -174,7 +164,7 @@ minetest.register_craftitem("mcl_potions:glass_bottle", {
 						return itemstack
 					end
 
-					take_from_cauldron(pointed_thing.under, node, itemstack, placer)
+					return take_from_cauldron(pointed_thing.under, node, itemstack, placer)
 				end
 			end
 		end
@@ -223,24 +213,6 @@ minetest.register_craftitem("mcl_potions:water", {
 				end
 			end
 
-			--[[
-			local cauldron = fill_cauldron(node.name, "mcl_core:water_source")
-			if cauldron then
-				local pname = placer:get_player_name()
-				if minetest.is_protected(pointed_thing.under, pname) then
-					minetest.record_protection_violation(pointed_thing.under, pname)
-					return itemstack
-				end
-				-- Increase water level of cauldron by 1
-				minetest.set_node(pointed_thing.under, {name=cauldron})
-				minetest.sound_play("mcl_potions_bottle_pour", {pos=pointed_thing.under, gain=0.5, max_hear_range=16}, true)
-				if minetest.is_creative_enabled(placer:get_player_name()) then
-					return itemstack
-				else
-					return "mcl_potions:glass_bottle"
-				end
-			end
-			--]]
 			if mcl_cauldrons.is_cauldron(node) then
 				-- apply water bottle to empty or water cauldron
 				-- anything else, replace content.
@@ -249,7 +221,7 @@ minetest.register_craftitem("mcl_potions:water", {
 					minetest.record_protection_violation(pointed_thing.under, pname)
 					return itemstack
 				end
-				give_to_cauldron(pointed_thing.under, node, itemstack, placer, "cauldron_water")
+				return give_to_cauldron(pointed_thing.under, node, itemstack, placer, "cauldron_water")
 			end
 		end