fix (maybe) the bad GC bug in luainterface?

LuaInterface/Lua/src/LuaDLL.cpp

@@ -618,6 +618,18 @@ namespace Lua511
         static void lua_atunlock(IntPtr luaState, LuaCSFunction^ unlockf);
 #endif
 
+		  //zero 22-jul-2017
+		static int lua_pushthread(IntPtr luaState)
+		{
+			return ::lua_pushthread(((lua_State *)luaState.ToPointer()));
+		}
+
+		static void lua_xmove(IntPtr from, IntPtr to, int n)
+		{
+			::lua_xmove(((lua_State *)from.ToPointer()), ((lua_State *)to.ToPointer()),n);
+		}
+
+
 		static void lua_pushnumber(IntPtr luaState, double number)
 		{
 			::lua_pushnumber(toState, number);

LuaInterface/LuaInterface/Lua.cs

@@ -68,7 +68,7 @@ namespace NLua
 			"-- Preload the mscorlib assembly							\n"+
 			"luanet.load_assembly(\"mscorlib\")							\n";
 
-		/*readonly */ IntPtr luaState;
+		/*readonly */ public IntPtr luaState; //zero 22-jul-2017 - made public
 		ObjectTranslator translator;
 
         LuaCSFunction panicCallback, lockCallback, unlockCallback;

LuaInterface/LuaInterface/ObjectTranslator.cs

@@ -803,6 +803,13 @@ namespace NLua
 			{
 				((LuaFunction)o).push(luaState);
 			}
+			//zero 22-jul-2017
+			else if (o is Lua)
+			{
+				var lua = o as Lua;
+				LuaDLL.lua_pushnil(lua.luaState);
+				LuaDLL.lua_xmove(lua.luaState, luaState, 1);
+			}
 			else 
 			{
 				pushObject(luaState,o,"luaNet_metatable");