Toggling maximize-window in a buffer running ansi-term

Question

I have been using the following function to maximize and unmaximize a window for two years now.

(defun toggle-maximize-buffer () "Toggle maximize buffer"
  (interactive)
  (if (= 1 (length (window-list)))
    (set-window-configuration my-saved-window-configuration)
    (progn
      (setq my-saved-window-configuration (current-window-configuration))
      (delete-other-windows))))

I have it bound to:

(define-key my-keys-minor-mode-map (kbd "C-M-u") 'toggle-maximize-buffer)

It always worked great, but today, after upgrading to the latest version of Emacs in OS X:

brew install emacs --HEAD --use-git-head --cocoa --with-gnutls --with-rsvg --with-imagemagick

this function stopped working properly when invoking it from a buffer running M-x ansi-term. More specifically, it works, but it moves cursor in my buffer whenever I do C-M-u RET. It happens regardless weather I am in character or line-mode in the ansi-term buffer.

The problem does not happen in any other type of buffer. Why am I having this problem, and what I can do about it?

In case it matters, here is the specific version I am using

GNU Emacs 25.0.50.1 (x86_64-apple-darwin14.1.0, NS appkit-1344.72 Version 10.10.2 (Build 14C1514))

Could this be a bug? Or is it perhaps a problem with my configuration?

Answer 1

Saving the last value of (point) and restoring it with goto-char should do the trick:

(defun toggle-maximize-buffer ()
  "Toggle maximize buffer"
  (interactive)
  (if (= 1 (length (window-list)))
      (progn
        (set-window-configuration my-saved-window-configuration)
        (goto-char my-saved-point))
    (setq my-saved-window-configuration (current-window-configuration)
          my-saved-point (point))
    (delete-other-windows)))

However this behaviour sounds like a bug to me. I'd check what the latest version of Emacs is that doesn't exhibit it and include that additionally to the other information in a M-x report-emacs-bug mail.