Bugfix:tables inside the Panel metatable were shared between panels as references and not as copies

api.lua

@@ -34,9 +34,10 @@ Panel = {
 
 function Panel:new(def)
     local panel = {}
+    local metapanel = clone_table(Panel)
 
-    setmetatable(panel, self)
-    self.__index = self
+    setmetatable(panel, metapanel)
+    metapanel.__index = metapanel
 
     if def.position then
       panel.background_def.position = def.position
@@ -206,8 +207,9 @@ function clone_table(orig)
     if orig_type == 'table' then
         copy = {}
         for orig_key, orig_value in pairs(orig) do
-            copy[orig_key] = orig_value
+            copy[clone_table(orig_key)] = clone_table(orig_value)
         end
+        setmetatable(copy, clone_table(getmetatable(orig)))
     else -- number, string, boolean, etc
         copy = orig
     end