Get rid of recursive call in default.dig_up

mods/default/functions.lua

@@ -293,12 +293,25 @@ minetest.register_abm({
 -- Dig upwards
 --
 
-function default.dig_up(pos, node, digger)
+local in_dig_up = false
+function default.dig_up(pos, node, digger, max_height)
+	if in_dig_up then return end -- Do not recurse
 	if digger == nil then return end
-	local np = {x = pos.x, y = pos.y + 1, z = pos.z}
-	local nn = minetest.get_node(np)
-	if nn.name == node.name then
-		minetest.node_dig(np, nn, digger)
+	max_height = max_height or 100
+
+	for y = pos.y + 1, pos.y + max_height do
+		local up_pos  = vector.new(pos.x, y, pos.z)
+		local up_node = minetest.get_node(up_pos)
+		if up_node.name == node.name then
+			in_dig_up = true
+			if not minetest.dig_node(up_pos, digger) then
+				in_dig_up = false
+				break
+			end
+			in_dig_up = false
+		else
+			break
+		end
 	end
 end
 

mods/default/init.lua

@@ -17,7 +17,7 @@ default.get_translator = S
 -- and avoids obscure, hard to debug runtime errors.
 -- This section should be updated before release and older checks can be dropped
 -- when newer ones are introduced.
-if ItemStack("").add_wear_by_uses == nil then
+if not minetest.features.node_interaction_actor then
 	error("\nThis version of Minetest Game is incompatible with your engine version "..
 		"(which is too old). You should download a version of Minetest Game that "..
 		"matches the installed engine version.\n")