Re: Strange error caused by post-command-hook.

[ishikawa]

Hi,

I tried the following mods to record what is inside post-command-hook.
But this is too verbose and I wonder if there is a way to
record the output of Fmessage() only to *Message* file
instead of showing it to the minibuffer.
My mailer may input line-break inside the format string of Fmessage().


From keyboard.c:

/* If we get an error while running the hook, cause the hook variable
   to be nil.  Also inhibit quits, so that C-g won't cause the hook
   to mysteriously evaporate.  */

void
safe_run_hooks (hook)
     Lisp_Object hook;
{
  int count = SPECPDL_INDEX ();

#if 0
  /* Local mods.
   * Tring to locate what erratic hook is set to post-command-hook.
   * Too verbose. I wonder if this could be only saved to Fmessage.
   */
  if(hook == Qpost_command_hook && ! NILP(Vpost_command_hook))
    {
      Lisp_Object args[3];
      args[0] = build_string ("Value of post-command hook in safe_run_hooks: 
%s");
      args[1] = Vpost_command_hook;
      Fmessage (2, args);
    }
#endif

  specbind (Qinhibit_quit, hook);

  internal_condition_case (safe_run_hooks_1, Qt, safe_run_hooks_error);

  unbind_to (count, Qnil);
}


Oh, maybe I can "copy" the value of post-command-hook and
re-print it after the error was detected...


ishikawa wrote:
ishikawa wrote:
> Dear Martin Rudalics,
>
> Thank you the suggestion. Before reading the following suggestion, I began
> modifying the keyboard.c.
>
> But I will try the following suggested tip first before compiling the
> modified keyboard.c source file.
>
> Chiaki Ishikawa
>
> PS: Things get really strange. I tried the following tip, and found that
> this doesn't really print anything of importance. It seems that the 
> processing
> that leads to the
> "<< Press Return to bury the buffer list >>"
> and probably the code that gets executed shortly after that is the 
> candidate for the culprit.
>
> Oh, wait, after a close look, I wonder what this 'tooltip-hide' is...
>
> To wit: This is the *Mesasges* buffer after I added the
> following hook:
>
>
> ((lambda nil (when post-command-hook (message "... %s" 
> post-command-hook))) tooltip-hide)
> <<< Press Return to bury the buffer list >>>
> Error in post-command-hook: (error Selecting deleted buffer) [3 times]
> <<< Press Return to bury the buffer list >>>
> Error in post-command-hook: (error Selecting deleted buffer)
> Mark set
> <<< Press Return to bury the buffer list >>>
> Error in post-command-hook: (error Selecting deleted buffer)
> Mark set
> <<< Press Return to bury the buffer list >>>
> Error in post-command-hook: (error Selecting deleted buffer)
> <<< Press Return to bury the buffer list >>>
> Error in post-command-hook: (error Selecting deleted buffer)
> ((lambda nil (when post-command-hook (message "... %s" 
> post-command-hook))) tooltip-hide)
> <<< Press Return to bury the buffer list >>>
> Error in post-command-hook: (error Selecting deleted buffer)
> <<< Press Return to bury the buffer list >>>
> Error in post-command-hook: (error Selecting deleted buffer)
> Mark set
> <<< Press Return to bury the buffer list >>>
> Error in post-command-hook: (error Selecting deleted buffer)
> <<< Press Return to bury the buffer list >>>
> Error in post-command-hook: (error Selecting deleted buffer)
> <<< Press Return to bury the buffer list >>>
> Error in post-command-hook: (error Selecting deleted buffer)
> Mark set
> <<< Press Return to bury the buffer list >>>
> Error in post-command-hook: (error Selecting deleted buffer)
> <<< Press Return to bury the buffer list >>>
> Error in post-command-hook: (error Selecting deleted buffer)
> Mark saved where search started [2 times]
> Auto-saving...
> Mark saved where search started [2 times]
> Saving file /home/ishikawa/emacs-22.1/src/keyboard.c...
> Wrote /home/ishikawa/emacs-22.1/src/keyboard.c
> (No changes need to be saved)
> <<< Press Return to bury the buffer list >>>
> Error in post-command-hook: (error Selecting deleted buffer)
> Wrote /home/ishikawa/.emacs
> <<< Press Return to bury the buffer list >>>
> Error in post-command-hook: (error Selecting deleted buffer)
> <<< Press Return to bury the buffer list >>>
> Error in post-command-hook: (error Selecting deleted buffer)
> <<< Press Return to bury the buffer list >>>
> Error in post-command-hook: (error Selecting deleted buffer)
> Mark set
> Mark activated
> Transient-mark-mode temporarily enabled
> Saved text from "((lambda nil (when post-command-hook (me"
> Mark set [2 times]
>
>
>
> martin rudalics wrote:
> >  > I have inserted the re-defined find-file in my .emacs file.
> >  > Once the problem returns, I will report the value of
> >  > post-command-hook.
> >  > (Aha, I see that the problem may happen before find-file gets 
> > executed.
> >  > How complicated...)
> >
> > I expected that.  Try the following (more intrusive):
> >
> > (add-hook 'pre-command-hook
> >       (lambda ()
> >         (when post-command-hook
> >           (message "... %s" post-command-hook))))