make rainbow staff check unswappable, make unswappable not change unbreakables

api/main_api.lua

@@ -9,12 +9,22 @@ nssm.unswappable_nodes[#nssm.unswappable_nodes+1] = "bones:bones"
 nssm.unswappable_nodes[#nssm.unswappable_nodes+1] = "default:chest_locked"
 
 nssm.unswappable_node = function (pos, node_list)
-    -- Return true if the original_node should not be swapped
-
     local _, node, original_node
     original_node = minetest.env:get_node(pos).name
 
-    if minetest.get_item_group(original_node) == "unbreakable" then
+    -- Return true if the original_node should not be swapped
+    if original_node ~= "air" and not minetest.registered_nodes[original_node] then
+        -- remnant unknown block
+        return true
+    end
+
+    local node_def = minetest.registered_nodes[original_node]
+
+    if original_node == "nssb:indistructible_morentir" then
+        minetest.debug(">>> "..dump(node_def))
+    end
+
+    if node_def and node_def.groups and node_def.groups.unbreakable then
         return true
     end
 

tools/rainbow_staff.lua

@@ -38,7 +38,7 @@ if not nssm.server_rainbow_staff then
             self.timer = self.timer or os.time()
 
             local pos = self.object:getpos()
-            if minetest.is_protected(pos, "") then
+            if nssm.unswappable_node(pos) then
                 return
             end