reset configurable before loading new options

frontend/ui/reader/configurable.lua

@@ -1,11 +1,25 @@
 local Configurable = {}
 
+function Configurable:new(o)
+    o = o or {}
+    setmetatable(o, self)
+    self.__index = self
+    return o
+end
+
+function Configurable:reset()
+    for key,value in pairs(self) do
+        if type(value) == "number" or type(value) == "string" then
+            self[key] = nil 
+        end
+    end
+end
+
 function Configurable:hash(sep)
     local hash = ""
     local excluded = {multi_threads = true,}
     for key,value in pairs(self) do
-		if type(value) == "number" or type(value) == "string" 
-			and not excluded[key] then
+        if type(value) == "number" or type(value) == "string" then 
             hash = hash..sep..value
         end
     end
@@ -13,6 +27,8 @@ function Configurable:hash(sep)
 end
 
 function Configurable:loadDefaults(config_options)
+    -- reset configurable before loading new options
+    self:reset()
     for i=1,#config_options do
         local options = config_options[i].options
         for j=1,#config_options[i].options do
@@ -31,7 +47,8 @@ function Configurable:loadSettings(settings, prefix)
             or type(value) == "table" then
             local saved_value = settings:readSetting(prefix..key)
             self[key] = (saved_value == nil) and self[key] or saved_value
-			--Debug("Configurable:loadSettings", "key", key, "saved value", saved_value,"Configurable.key", self[key])
+            --Debug("Configurable:loadSettings", "key", key, "saved value", 
+            --saved_value,"Configurable.key", self[key])
         end
     end
     --Debug("loaded config:", dump(Configurable))