RE: Changes for emacs 28

[Drew Adams]

> Sadly we have <mouse-3> bind to mouse-save-then-kill which I don't find
> useful at all, but maybe somebody will complain if we change it to
> C-<mouse-3> and move the panel to <mouse-3>.

1. `mouse-save-then-kill' is very useful, IMO.

2. Library `mouse3.el' gives you any behavior you want
   for mouse-3 - in particular, popup context menus of
   any sort.

   AND it gives you the usual `mouse-save-then-kill'
   behavior.

   IOW, you don't have to choose one or the other, you
   can have both: choose what you want on the fly.

https://www.emacswiki.org/emacs/Mouse3

https://www.emacswiki.org/emacs/download/mouse3.el


This option lets you do whatever you want with a second
mouse-3 click.  And option `mouse3-double-click-command'
does the same thing for a double-click.

,----
| mouse3-second-click-default-command is a variable defined in `mouse3.el'.
| Its value is mouse3-popup-menu
| 
| Command used for a second `mouse-3' click at the same location.
| The command must accept 2 args: mouse click event and prefix arg.
| 
| This is a default value, which can be programmatically overridden in
| various contexts.  This option is used only if variable
| `mouse3-save-then-kill-command' is nil.
| 
| Two particular values:
|  `mouse3-popup-menu': Pop up a menu of actions on the region.
|  `mouse3-kill/delete-region': Kill or delete the region, according to
|                               `mouse-drag-copy-region'.
| 
| See also `mouse3-double-click-command'.  You will probably want to
| customize these two options together.  To make either a no-op, set the
| value to command `ignore'.
| 
| Note that setting `mouse3-double-click-command' to `mouse3-popup-menu'
| and `mouse3-second-click-default-command' to
| `mouse3-kill/delete-region' is not recommended, because in Emacs a
| double-click event is always preceded automatically by the associated
| single-click event.  See `(elisp) Repeat Events'.
| 
| You can customize this variable.
`----