Merge branch '2209-fix-parse-res-text' into 'master'

gthreadedresolver: Fix logic in parse_res_text()

Closes #2209

See merge request GNOME/glib!1664

gio/gthreadedresolver.c

@@ -620,7 +620,7 @@ parse_res_txt (guchar  *answer,
   while (at < end)
     {
       len = *(at++);
-      if (len > at - end)
+      if (len > (gsize) (end - at))
         break;
       g_ptr_array_add (array, g_strndup ((gchar *)at, len));
       at += len;