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

[Alan Mackenzie]

Hello, Emacs.

In the emacs-27 branch, in X Windows, from a terminal:

(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.

-- 
Alan Mackenzie (Nuremberg, Germany).