Re: Moving the mouse clears the minibuffer in isearch mode

[Richard Stallman]

        (setq toolbar-gud-tips-p t)
        C-x C-f somefile.c   (any existing C file will do!)
        C-s
        move the mouse

    Now the minibuffer is blank, but isearch is still active.

It does not happen for me: moving the mouse does not clear the
minibuffer.  (I presume you meant tooltip-gud-tips-p, since there is
no built-in variable toolbar-gud-tips-p.)