bug#32990: 26.1.50; isearch-forward + t-m-m/mark-active doc

[Juri Linkov]

> To see the positive effect of that statement, is setting
> `isearch-allow-scroll' to t required?

This is required as long as it's not the default.

> For me, the following recipe still has issues, even with that line
> added to the patch:
>
> emacs -Q
> M-x set-variable isearch-allow-scroll t
> C-r M-` i
>
> The "Isearch" menu should now be shown in the *Completions* window,
> but instead Isearch actually searches for the character "i" in the
> minibuffer.  If we can inhibit that then we should be fine.  (It looks
> like Isearch is not happy about commands switching the current buffer
> behind its back.)

I tried:

C-r M-` down i

and it works fine, i.e. typing an arrow key after M-`
somehow suspends the isearch mode, and you can continue
typing letters in tmm-menu.

But maybe we should suspend isearch explicitly with something like

(defun isearch-tmm ()
  (interactive)
  (with-isearch-suspended (tmm-menubar)))

(define-key isearch-mode-map "\M-`" 'isearch-tmm)

PS: I noticed that tmm menus are reversed, so you have to type `up'
key for a previous tmm-menu item, not `down' like in other menus.