bug#27819: invoking `artist-mouse-choose-operation' gives "if: Wrong type argument: listp, 110"

[Stephen Berman]

On Tue, 25 Jul 2017 14:25:19 +0200 Stephen Berman <stephen.berman@gmx.net> 
wrote:

> On Tue, 25 Jul 2017 18:49:08 +0800 Shiyao Ma <i@introo.me> wrote:
>
>> Hi,
>>
>> I am on macOS emacs25, and using artist-mode.
>>
>> when invoking `artist-mouse-choose-operation', I got this error message: if:
>> Wrong type argument: listp.
>
> I can reproduce the error by invoking the command like this:
> `M-x artist-mouse-choose-operation'.

Actually, I overlooked the last piece of the error message in the
Subject line "if: Wrong type argument: listp, 110".  What I see with
`M-x artist-mouse-choose-operation RET' is "if: Wrong type argument:
listp, 13", where 13 is the character code for RET.  110 is the
character code of the `n' key; the only way I can see that this
specific error occurred is if `artist-mouse-choose-operation' was bound
to `n'.  So to Shiyao Ma: Did you making such a binding?  If not, what
exactly did you do to get the error in the Subject line?

> The command is intended to be invoked with down-mouse-2 (that's what
> it's bound to in artist-mode-map).  
>
>> How to solve this?
>
> This is one way:
>
> diff --git a/lisp/textmodes/artist.el b/lisp/textmodes/artist.el
> index 596570ca4e..cdc2af4a7a 100644
> --- a/lisp/textmodes/artist.el
> +++ b/lisp/textmodes/artist.el
> @@ -4889,7 +4889,7 @@ artist-mouse-choose-operation
>       (select-window (posn-window (event-start last-input-event)))
>       (list last-input-event
>          (if (display-popup-menus-p)
> -            (x-popup-menu last-nonmenu-event artist-popup-menu-table)
> +            (x-popup-menu t artist-popup-menu-table)
>            'no-popup-menus))))
>  
>    (if (eq op 'no-popup-menus)
>
>
> A possible disadvantage of this fix is that typing `M-x
> artist-mouse-choose-operation' will pop up the menu wherever the mouse
> pointer is, which on a graphical display could be anywhere on the
> screen, not necessarily within the Emacs window or even frame displaying
> the artist-mode buffer.

I think this is less disturbing that getting the error, and since, when
invoking the command with down-mouse-2 as intended, passing
last-nonmenu-event has the same effect as passing t (i.e., popping up
the menu where the mouse pointer is), I see no problem with making this
change.  (It also DTRT if `artist-mouse-choose-operation' is rebound,
though if that isn't how the error message showed 110, then something
else must be going on.)  So if there are no objections, I'll push it to
master.

Steve Berman