Created attachment 4503 
Set simple to NULL after error

_xfce_rc_config_new() crashes if there is an error parsing a config file. The code is:

  XfceRcSimple *simple = NULL;
  ...
  for (p = paths; *p != NULL; ++p)
    {
      ...
      simple = _xfce_rc_simple_new (simple, *p, TRUE);
      if (!_xfce_rc_simple_parse (simple))
        {
          g_critical ("Failed to parse file %s, ignoring.", *p);
          xfce_rc_close (XFCE_RC (simple));
          continue;
        }
        ...
    }

xfce_rc_close() frees the memory pointed to by simple, so in the next iteration of the loop, simple is a dangling pointer and a crash is a typical result. Setting simple to NULL on error would be one way to avoid the crash, I have attached that as a patch and tested it.

Observed in 4.8.2, but the code error appears to still exist in git master.