# HG changeset patch
# User jbe
# Date 1425163880 -3600
# Node ID ba596113a7991da784e8998683ff338caae83637
# Parent  4ab91adeab6f479733edde4d0a8af5f4f3a2d458
Exception for setting global variables

diff -r 4ab91adeab6f -r ba596113a799 framework/bin/mcp.lua
--- a/framework/bin/mcp.lua	Sat Feb 28 23:37:27 2015 +0100
+++ b/framework/bin/mcp.lua	Sat Feb 28 23:51:20 2015 +0100
@@ -4,6 +4,7 @@
 
 -- allow control of global environment
 local _G = _G
+local allowed_globals = {}
 local global_metatable = {
   __index = _G,
   __newindex = function(self, key, value)
@@ -163,20 +164,17 @@
       end
     end
     if self == _ENV then
-      _G[key] = false  -- allow writing global variable
+      allowed_globals[key] = true
     end
     if merge and try_exec(merge_path .. ".lua") then
     elseif merge and try_dir(merge_path .. "/") then
     elseif try_exec(path .. ".lua") then
     elseif try_dir(path .. "/") then
     else end
-    local value = rawget(self, key)
-    if self == _ENV and value == false then
-      _G[key] = nil
-      return nil
-    else
-      return value
+    if self == _ENV then
+      allowed_globals[key] = nil
     end
+    return rawget(self, key)
   end
   install_autoloader(_G, nil, "")
   try_exec(WEBMCP_FRAMEWORK_PATH .. "env/__init.lua")
@@ -191,8 +189,11 @@
 end
 
 -- prohibit (unintended) definition of new global variables
-function global_metatable.__newindex()
-  error("Setting of global variable prohibited", 2)
+function global_metatable.__newindex(self, key, value)
+  if not allowed_globals[key] then
+    error("Setting of global variable prohibited", 2)
+  end
+  rawset(self, key, value)
 end
 
 -- execute configurations and pre-fork initializers