Before:
  if (!qname_prefix(code).id()) {
    gchar *svg_name = g_strconcat(prefix, ":", g_quark_to_string(code), NULL);
    repr->setCodeUnsafe(g_quark_from_string(svg_name));
    g_free(svg_name);
  }

After:
  if (!qname_prefix(code).id()) {
    TempGtkStringPtr svg_name(g_strconcat(prefix, ":", g_quark_to_string(code), NULL));
    repr->setCodeUnsafe(g_quark_from_string(svg_name));
  }