in Emacs, what's the best way for keyboard-escape-quit not destroy other windows?

Question

EDIT: I understand there is keyboard-quit (which is normally bound to C-g); but I'm more interested to know about how one deals with editing functions that come with Emacs (like in this case). I run into this kind of situations from time to time when I want to change just a little bit of some build-in functions.

In emacs, when you hit M-ESC ESC (or ESC three times), you can get out of a lots of situations like transient-mark, etc. But I habitually hit the escape key (I actually remap this to a single hit of the escape key) more than I intended, and that ends up killing my windows configuration, which is quite annoying. The function keyboard-escape-quit is defined in simple.el:

(defun keyboard-escape-quit ()
  "Exit the current \"mode\" (in a generalized sense of the word).
This command can exit an interactive command such as `query-replace',
can clear out a prefix argument or a region,
can get out of the minibuffer or other recursive edit,
cancel the use of the current buffer (for special-purpose buffers),
or go back to just one window (by deleting all but the selected window)."
  (interactive)
  (cond ((eq last-command 'mode-exited) nil)
    ((> (minibuffer-depth) 0)
     (abort-recursive-edit))
    (current-prefix-arg
     nil)
    ((and transient-mark-mode mark-active)
     (deactivate-mark))
    ((> (recursion-depth) 0)
     (exit-recursive-edit))
    (buffer-quit-function
     (funcall buffer-quit-function))
    ((not (one-window-p t))
     (delete-other-windows))
    ((string-match "^ \\*" (buffer-name (current-buffer)))
     (bury-buffer))))

And I can see that I don't want the lines:

    ((not (one-window-p t))
     (delete-other-windows))

But what is the best way to modify this function? I can see only two ways: 1) modify simple.el 2) copy this function to my .emacs file and do the modifications there. Both ways are not really good; ideally I would like to see something on the line of defadvice, but I can't see how I can do it in this case.

Answer 1

You could use around advice and redefine the offending function to do what you want (i.e. one-window-p should always return t):

(defadvice keyboard-escape-quit (around my-keyboard-escape-quit activate)
  (let (orig-one-window-p)
    (fset 'orig-one-window-p (symbol-function 'one-window-p))
    (fset 'one-window-p (lambda (&optional nomini all-frames) t))
    (unwind-protect
        ad-do-it
      (fset 'one-window-p (symbol-function 'orig-one-window-p)))))

This kind of acts like a (let ...) but has to be more complicated because you need to override a function for a limited scope instead of a variable.