Problem with tooltip frame parameters

[David PONCE]

Hi All,

I recently noticed that customization of `tooltip-frame-parameters' no
more works.  I found that, after `x-show-tip' is called in
`tooltip-show', all the `tooltip-frame-parameters' symbols are changed
to nil!

It is easy to reproduce:

emacs -Q

In the *scratch* buffer eval:

tooltip-frame-parameters

==> ((name . "tooltip") (internal-border-width . 2) (border-width . 1))

Move the mouse on the tool bar to show a tooltip.  Then eval again:

tooltip-frame-parameters

==> ((nil . "tooltip") (nil . 2) (nil . 1))

Do others observe that?  If so, I wonder if that could be a side
effect of a recent change in the function `x_get_arg' in frame.c that
introduced this code:

  tem = Fassq (param, alist);

  if (!NILP (tem))
    {
      /* If we find this parm in ALIST, clear it out
         so that it won't be "left over" at the end.  */
#ifndef WINDOWSNT /* w32fns.c has not yet been changed to cope with this.  */
      Lisp_Object tail;
      XSETCAR (tem, Qnil);
      /* In case the parameter appears more than once in the alist,
         clear it out.  */
      for (tail = alist; CONSP (tail); tail = XCDR (tail))
        if (CONSP (XCAR (tail))
            && EQ (XCAR (XCAR (tail)), param))
          XSETCAR (XCAR (tail), Qnil);
#endif
    }

Particularly, the XSETCAR (tem, Qnil); statement might be the culprit.

Sincerely,
David

In GNU Emacs 22.0.50.1 (i686-pc-linux-gnu, GTK+ Version 2.6.10)
 of 2006-03-10 on localhost
X server distributor `The X.Org Foundation', version 11.0.60802000
configured using `configure '--with-gtk''

Important settings:
  value of $LC_ALL: nil
  value of $LC_COLLATE: nil
  value of $LC_CTYPE: nil
  value of $LC_MESSAGES: nil
  value of $LC_MONETARY: nil
  value of $LC_NUMERIC: nil
  value of $LC_TIME: nil
  value of $LANG: en_US.UTF-8
  locale-coding-system: utf-8
  default-enable-multibyte-characters: t