bug#43966: Isearch, C-g and f10 interact to leave Isearch in an inconsistent state.

[Juri Linkov]

> (i) emacs -Q -nw.
> (ii) M-x menu-bar-mode (to turn it off).
> (iii) Visit a file.
> (iv) C-s <some characters>.
> (v) f10 to open the menu.
>
> (vi) C-x o once or twice to move to the menu window.
> (vii) C-g.  (This leaves the menu window in place).
> (viii) C-x o to move to the minibuffer.
> (ix) C-g.  (This deletes the menu window).
>
> There is now one window open, that displaying the file buffer.
> According to the mode line, Isearch is still active, and indeed further
> characters can be typed onto the search string.
>
> However, point can be freely moved by, e.g., C-f or C-b., without
> terminating the Isearch.  This is a bug.

This is because 'isearch-menu-bar-commands' contains 'menu-bar-open'
added in bug#32990 to allow invocation of isearch commands from menu.