Bug with key echo.

Bug with key echo.

[David Kastrup]

Execute the following two commands.

(define-key ctl-x-map "\C-p" nil)
(define-key ctl-x-map "\C-p\C-p" (lambda nil (interactive) (y-or-n-p "Woozle ")))

Now type C-x C-p and wait until the key echo appears.  Then type C-p
again.

Instead of a display of
Woozle (y or n)
in the echo area, you get
C-x C-p C-p-
which makes it somewhat hard to guess at the question.  This bug has
been plagueing me for years, but I have not been able to come up with
a working test case for it.

It seems to be a combination of intermediate map and multiple key
stroke following that is involved here.

-- 
David Kastrup, Kriemhildstr. 15, 44793 Bochum

Re: Bug with key echo.

[Richard Stallman]

    Execute the following two commands.

    (define-key ctl-x-map "\C-p" nil)
    (define-key ctl-x-map "\C-p\C-p" (lambda nil (interactive) (y-or-n-p "Woozle ")))

    Now type C-x C-p and wait until the key echo appears.  Then type C-p
    again.

Does this fix it?

*** xdisp.c	29 Jan 2005 11:51:48 -0500	1.974
--- xdisp.c	01 Feb 2005 05:44:57 -0500	
***************
*** 8085,8090 ****
--- 8085,8091 ----
  
    /* Last displayed message is now the current message.  */
    echo_area_buffer[1] = echo_area_buffer[0];
+   echo_message_buffer = Qnil;
  
    /* Prevent redisplay optimization in redisplay_internal by resetting
       this_line_start_pos.  This is done because the mini-buffer now

Re: Bug with key echo.

[David Kastrup]

Richard Stallman <rms@gnu.org> writes:

>     Execute the following two commands.
>
>     (define-key ctl-x-map "\C-p" nil)
>     (define-key ctl-x-map "\C-p\C-p" (lambda nil (interactive) (y-or-n-p "Woozle ")))
>
>     Now type C-x C-p and wait until the key echo appears.  Then type C-p
>     again.
>
> Does this fix it?
>
> *** xdisp.c	29 Jan 2005 11:51:48 -0500	1.974
> --- xdisp.c	01 Feb 2005 05:44:57 -0500	
> ***************
> *** 8085,8090 ****
> --- 8085,8091 ----
>   
>     /* Last displayed message is now the current message.  */
>     echo_area_buffer[1] = echo_area_buffer[0];
> +   echo_message_buffer = Qnil;
>   
>     /* Prevent redisplay optimization in redisplay_internal by resetting
>        this_line_start_pos.  This is done because the mini-buffer now

It appears to do so for the real-world case from which I distilled the
above bug recipe.  I have not tested thoroughly for side effects,
though.

-- 
David Kastrup, Kriemhildstr. 15, 44793 Bochum

Re: Bug with key echo.

[Richard Stallman]

    It appears to do so for the real-world case from which I distilled the
    above bug recipe.  I have not tested thoroughly for side effects,
    though.

Please test as much as is practical in the next couple of days.
If you don't find a problem in that time, I'll install the change.