1 files changed, 143 insertions, 0 deletions
diff --git a/www/wiki/extensions/Scribunto/includes/engines/LuaCommon/lualib/mwInit.lua b/www/wiki/extensions/Scribunto/includes/engines/LuaCommon/lualib/mwInit.lua
new file mode 100644
index 00000000..c1667efb
--- /dev/null
+++ b/www/wiki/extensions/Scribunto/includes/engines/LuaCommon/lualib/mwInit.lua
@@ -0,0 +1,143 @@
+-- This file is for anything that needs to be set up before a Lua engine can
+-- start. Things in this file may run more than once, so avoid putting anything
+-- other than function definitions in it. Also, because this can run before
+-- PHP can do anything, mw_interface is unavailable here.
+
+mw = mw or {}
+
+-- Extend pairs and ipairs to recognize __pairs and __ipairs, if they don't already
+do
+	local t = {}
+	setmetatable( t, { __pairs = function() return 1, 2, 3 end } )
+	local f = pairs( t )
+	if f ~= 1 then
+		local old_pairs = pairs
+		pairs = function ( t )
+			local mt = getmetatable( t )
+			local f, s, var = ( mt and mt.__pairs or old_pairs )( t )
+			return f, s, var
+		end
+		local old_ipairs = ipairs
+		ipairs = function ( t )
+			local mt = getmetatable( t )
+			local f, s, var = ( mt and mt.__ipairs or old_ipairs )( t )
+			return f, s, var
+		end
+	end
+end
+
+-- Reduce precision on os.clock to mitigate timing attacks
+do
+	local old_clock = os.clock
+	os.clock = function ()
+		local v = old_clock()
+		return math.floor( v * 50000 + 0.5 ) / 50000
+	end
+end
+
+--- Do a "deep copy" of a table or other value.
+function mw.clone( val )
+	local tableRefs = {}
+	local function recursiveClone( val )
+		if type( val ) == 'table' then
+			-- Encode circular references correctly
+			if tableRefs[val] ~= nil then
+				return tableRefs[val]
+			end
+
+			local retVal
+			retVal = {}
+			tableRefs[val] = retVal
+
+			-- Copy metatable
+			if getmetatable( val ) then
+				setmetatable( retVal, recursiveClone( getmetatable( val ) ) )
+			end
+
+			for key, elt in pairs( val ) do
+				retVal[key] = recursiveClone( elt )
+			end
+			return retVal
+		else
+			return val
+		end
+	end
+	return recursiveClone( val )
+end
+
+--- Make isolation-safe setfenv and getfenv functions
+--
+-- @param protectedEnvironments A table where the keys are protected environment
+--    tables. These environments cannot be accessed with getfenv(), and
+--    functions with these environments cannot be modified or accessed using
+--    integer indexes to setfenv(). However, functions with these environments
+--    can have their environment set with setfenv() with a function value
+--    argument.
+--
+-- @param protectedFunctions A table where the keys are protected functions,
+--    which cannot have their environments set by setfenv() with a function
+--    value argument.
+--
+-- @return setfenv
+-- @return getfenv
+function mw.makeProtectedEnvFuncs( protectedEnvironments, protectedFunctions )
+	local old_setfenv = setfenv
+	local old_getfenv = getfenv
+
+	local function my_setfenv( func, newEnv )
+		if type( func ) == 'number' then
+			local stackIndex = math.floor( func )
+			if stackIndex <= 0 then
+				error( "'setfenv' cannot set the global environment, it is protected", 2 )
+			end
+			if stackIndex > 10 then
+				error( "'setfenv' cannot set an environment at a level greater than 10", 2 )
+			end
+
+			-- Add one because we are still in Lua and 1 is right here
+			stackIndex = stackIndex + 1
+
+			local env = old_getfenv( stackIndex )
+			if env == nil or protectedEnvironments[ env ] then
+				error( "'setfenv' cannot set the requested environment, it is protected", 2 )
+			end
+			func = old_setfenv( stackIndex, newEnv )
+		elseif type( func ) == 'function' then
+			if protectedFunctions[func] then
+				error( "'setfenv' cannot be called on a protected function", 2 )
+			end
+			local env = old_getfenv( func )
+			if env == nil or protectedEnvironments[ env ] then
+				error( "'setfenv' cannot set the requested environment, it is protected", 2 )
+			end
+			old_setfenv( func, newEnv )
+		else
+			error( "'setfenv' can only be called with a function or integer as the first argument", 2 )
+		end
+		return func
+	end
+
+	local function my_getfenv( func )
+		local env
+		if type( func ) == 'number' then
+			if func <= 0 then
+				error( "'getfenv' cannot get the global environment" )
+			end
+			env = old_getfenv( func + 1 )
+		elseif type( func ) == 'function' then
+			env = old_getfenv( func )
+		else
+			error( "'getfenv' cannot get the global environment" )
+		end
+
+		if protectedEnvironments[env] then
+			return nil
+		else
+			return env
+		end
+	end
+
+	return my_setfenv, my_getfenv
+end
+
+return mw