LUA_PushLightUserdata takes the fun out of lib_cvFindVar

src/lua_consolelib.c

@@ -431,23 +431,9 @@ static int lib_cvRegisterVar(lua_State *L)
 
 static int lib_cvFindVar(lua_State *L)
 {
-	consvar_t *cv;
-	if (( cv = CV_FindVar(luaL_checkstring(L,1)) ))
-	{
-		lua_settop(L,1);/* We only want one argument in the stack. */
-		lua_pushlightuserdata(L, cv);/* Now the second value on stack. */
-		luaL_getmetatable(L, META_CVAR);
-		/*
-		The metatable is the last value on the stack, so this
-		applies it to the second value, which is the cvar.
-		*/
-		lua_setmetatable(L,2);
-		lua_pushvalue(L,2);
+	LUA_PushLightUserdata(L, CV_FindVar(luaL_checkstring(L,1)), META_CVAR);
 	return 1;
 }
-	else
-		return 0;
-}
 
 // CONS_Printf for a single player
 // Use 'print' in baselib for a global message.

src/lua_script.c

@@ -568,6 +568,28 @@ fixed_t LUA_EvalMath(const char *word)
 	return res;
 }
 
+/*
+LUA_PushUserdata but no userdata is created.
+You can't invalidate it therefore.
+*/
+
+void LUA_PushLightUserdata (lua_State *L, void *data, const char *meta)
+{
+	if (data)
+	{
+		lua_pushlightuserdata(L, data);
+		luaL_getmetatable(L, meta);
+		/*
+		The metatable is the last value on the stack, so this
+		applies it to the second value, which is the userdata.
+		*/
+		lua_setmetatable(L, -2);
+		lua_pushvalue(L, -1);
+	}
+	else
+		lua_pushnil(L);
+}
+
 // Takes a pointer, any pointer, and a metatable name
 // Creates a userdata for that pointer with the given metatable
 // Pushes it to the stack and stores it in the registry.

src/lua_script.h

@@ -46,6 +46,7 @@ void LUA_LoadLump(UINT16 wad, UINT16 lump);
 void LUA_DumpFile(const char *filename);
 #endif
 fixed_t LUA_EvalMath(const char *word);
+void LUA_PushLightUserdata(lua_State *L, void *data, const char *meta);
 void LUA_PushUserdata(lua_State *L, void *data, const char *meta);
 void LUA_InvalidateUserdata(void *data);
 void LUA_InvalidateLevel(void);