Prevent mouse-3 on mode-line from closing the window

Question

From https://www.gnu.org/software/emacs/manual/html_node/emacs/Mode-Line-Mouse.html :

mouse-3 on a mode line deletes the window it belongs to. If the frame has only one window, it does nothing.

I want to disable this behavior. How do I do it?

Answer 1

To unbind it:

(global-set-key [mode-line mouse-3] nil)

To bind it to a different command:

(global-set-key [mode-line mouse-3] 'my-favorite-command)

How did I find this?

C-h k, then right-click the mouse on the mode-line, somewhere where there is no text.

That tells you:

<mode-line> <mouse-3> (translated from <down-mouse-3> <mouse-3>) at that spot runs the command mouse-delete-window, which is an interactive compiled Lisp function in mouse.el.

It is bound to <mode-line> <mouse-3>.

(mouse-delete-window CLICK)

Delete the window you click on.

Do nothing if the frame has just one window.

This command must be bound to a mouse click.

If you then click the mouse.el link it takes you to the command definition. Searching for that command name in the same file, you come across this:

(global-set-key [mode-line mouse-3] 'mouse-delete-window)

You can copy that, changing the command name or replacing it by nil.

---

Update: I should have also mentioned what @Faried Nawaz mentions, which is a simpler way to unbind the key: use global-unset-key. (So please consider upvoting that answer too.) The result is the same as binding the command to nil. Here is the definition (from subr.el):

(defun global-unset-key (key)
  "Remove global binding of KEY.
KEY is a string or vector representing a sequence of keystrokes."
  (interactive "kUnset key globally: ")
  (global-set-key key nil))

Answer 2

Evaluate this:

(global-unset-key [mode-line mouse-3])

You might want to M-x customize-variable RET mode-line-default-help-echo RET as well, but that's optional.