bug#49784: 27.2; mouse-2 error with "No cross-reference here"

bug#49784: 27.2; mouse-2 error with "No cross-reference here"

[Robert Morelli]

This might be related to bug 11174 reported 9 years ago.

To reproduce, bind:
(global-set-key (kbd "<mouse-2>")
(lambda (click)
(interactive "e")))

Then, click with mouse-2 in a *Help* buffer.



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bug#49784: 27.2; mouse-2 error with "No cross-reference here"

[Lars Ingebrigtsen]

Robert Morelli <morelli@flux.utah.edu> writes:

> This might be related to bug 11174 reported 9 years ago.
>
> To reproduce, bind:
> (global-set-key (kbd "<mouse-2>")
> (lambda (click)
> (interactive "e")))
>
> Then, click with mouse-2 in a *Help* buffer.

Sorry; I don't understand this bug report.  Why do you need to bind
<mouse-2>?  <mouse-2> is already bound in *Help* buffers, and gives you
that error (if you're not clicking on a button).

Do you just wish to rebind <mouse-2> in all buffers?  Then you should
probably rebind <down-mouse-2> instead.

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no

bug#49784: 27.2; mouse-2 error with "No cross-reference here"

[Eli Zaretskii]

> From: Robert Morelli <morelli@flux.utah.edu>
> Date: Fri, 30 Jul 2021 11:20:52 -0600
> 
> This might be related to bug 11174 reported 9 years ago.
> 
> To reproduce, bind:
> (global-set-key (kbd "<mouse-2>")
> (lambda (click)
> (interactive "e")))
> 
> Then, click with mouse-2 in a *Help* buffer.

Why is this a bug?  *Help* buffers have mouse-2 bound locally to a
command, and local bindings take precedence over global ones.

bug#49784: 27.2; mouse-2 error with "No cross-reference here"

[Lars Ingebrigtsen]

Eli Zaretskii <eliz@gnu.org> writes:

> Why is this a bug?  *Help* buffers have mouse-2 bound locally to a
> command, and local bindings take precedence over global ones.

I don't quite understand the reported issue either, but it's pretty odd
for help-mode to bind mouse-2 -- we generally don't do that in buffers;
only buttons have mouse bindings.

Especially with this not very helpful command:

;; The doc string is meant to explain what buttons do.
(defun help-follow-mouse ()
  "Follow the cross-reference that you click on."
  (interactive)
  (error "No cross-reference here"))

I guess the point is to...  not say

Buffer is read-only: #<buffer *Help*>

to be helpful?  It might just confuse more than it helps.

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no

bug#49784: 27.2; mouse-2 error with "No cross-reference here"

[Eli Zaretskii]

> From: Lars Ingebrigtsen <larsi@gnus.org>
> Cc: Robert Morelli <morelli@flux.utah.edu>,  49784@debbugs.gnu.org
> Date: Fri, 30 Jul 2021 20:54:08 +0200
> 
> Especially with this not very helpful command:
> 
> ;; The doc string is meant to explain what buttons do.
> (defun help-follow-mouse ()
>   "Follow the cross-reference that you click on."
>   (interactive)
>   (error "No cross-reference here"))
> 
> I guess the point is to...  not say
> 
> Buffer is read-only: #<buffer *Help*>
> 
> to be helpful?  It might just confuse more than it helps.

Perhaps the comment before the function hints on why this was done
that way.  IOW, if this binding didn't exist, what would C-h show for
mouse-2, and how?

bug#49784: 27.2; mouse-2 error with "No cross-reference here"

[Lars Ingebrigtsen]

Eli Zaretskii <eliz@gnu.org> writes:

>> ;; The doc string is meant to explain what buttons do.
>> (defun help-follow-mouse ()
>>   "Follow the cross-reference that you click on."
>>   (interactive)
>>   (error "No cross-reference here"))
>> 
>> I guess the point is to...  not say
>> 
>> Buffer is read-only: #<buffer *Help*>
>> 
>> to be helpful?  It might just confuse more than it helps.
>
> Perhaps the comment before the function hints on why this was done
> that way.  IOW, if this binding didn't exist, what would C-h show for
> mouse-2, and how?

It'd say

It is bound to <mouse-2>.

(mouse-yank-primary CLICK)

like in any other buffer it's not bound.  I understand that the binding
was done to be helpful, but I'm just not sure that it's helpful to make
*Help* buffers behave weirdly.

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no

bug#49784: 27.2; mouse-2 error with "No cross-reference here"

[Lars Ingebrigtsen]

Lars Ingebrigtsen <larsi@gnus.org> writes:

> like in any other buffer it's not bound.  I understand that the binding
> was done to be helpful, but I'm just not sure that it's helpful to make
> *Help* buffers behave weirdly.

After pondering this some more, I don't think the having `C-h <mouse-2>'
in *Help* buffers giving a vaguely helpful (but ultimately confusing)
message warrants binding useless commands (that get in the way of
legitimate use cases, like globally rebinding <mouse-2>) makes that much
sense.

So I've now removed the bindings and made the commands obsolete.  We'll
see whether there's any negative reactions to this, I guess...

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no