fixed stack overflow for 3-or-deeper hierarchies on super construction

class.lua

@@ -100,14 +100,24 @@ local function class(config)
 	--get the inherited class for super calls if/as needed
 	--allows overrides that still refer to superclass behaviour
 	c.__super = extends
-	--nop by default
+
-	function c:super() end
+	--perform a (partial) super construction for an instance
+	--for any nested super calls, it'll call the relevant one in the
+	--heirarchy, assuming no super calls have been missed
+	function c:super(...)
+		if not c.__super then return end
+		--hold reference so we can restore
+		local current_super = c.__super
+		--push next super
+		c.__super = c.__super.__super
+		--call
+		current_super.new(self, ...)
+		--restore
+		c.__super = current_super
+	end
+
 
 	if c.__super then
-		--perform a super construction for an instance
-		function c:super(...)
-			c.__super.new(self, ...)
-		end
 		--implement superclass interface
 		implement(c, c.__super)
 	end