patch 7.4.954
Problem:    When using Lua there may be a crash. (issue #468)
Solution:   Avoid using an unitialized tv. (Yukihiro Nakadaira)
diff --git a/src/if_lua.c b/src/if_lua.c
index bc2d6c3..e94c96d 100644
--- a/src/if_lua.c
+++ b/src/if_lua.c
@@ -1561,14 +1561,15 @@
 	{
 	    tv.v_type = VAR_LIST;
 	    tv.vval.v_list = (list_T *) lua_touserdata(L, 4); /* key */
+	    abort = set_ref_in_item(&tv, copyID, NULL, NULL);
 	}
 	else if (lua_rawequal(L, -1, 3)) /* dict? */
 	{
 	    tv.v_type = VAR_DICT;
 	    tv.vval.v_dict = (dict_T *) lua_touserdata(L, 4); /* key */
+	    abort = set_ref_in_item(&tv, copyID, NULL, NULL);
 	}
 	lua_pop(L, 2); /* metatable and value */
-	abort = set_ref_in_item(&tv, copyID, NULL, NULL);
     }
     lua_pushinteger(L, abort);
     return 1;