bug#62250: 29.0.60; Allow context menu from text properties to not override everything

[Augusto Stoffel]

On Sat, 18 Mar 2023 at 10:31, Eli Zaretskii wrote:

>> Alternatively, it can return a completely new menu.  In
>> this case, no further functions from `context-menu-functions' are
>> called.

> What if a Lisp program _does_ want to override the menu specified by
> context-menu-functions? or what if it wants the menu specified by the
> text property to be the _last_ entry, not the first?

It's explained in the bit I kept: you ignore the MENU argument and
return a totally new keymap / not `eq'.  Adding things at the beginning
or end of a menu is an option that easy-menu-add-item etc already offer,
right?

Note that currently a member of context-menu-functions cannot override
the menu, and a context-menu-function cannot _not_ override it.  My
suggestions allows all possibilities.