🚀 go-pugleaf

I noticed the following in etc/NEWS for 19.26

	** In Shell mode and other comint modes, C-a has now returned to
	its ordinary meaning: move to the beginning of the line.
	Use C-c C-a to move to the end of the prompt.

I agree the previous behavior was undesirable.  The following, bound
via comint-mode-hook, has always worked flawlessly for me:


(defun beginning-of-input ()
  "If within command input area, move point to start of input.
Otherwise just do beginning-of-line."
  (interactive)
  (let* ((proc (get-buffer-process (current-buffer)))
	 (p (and proc (marker-position (process-mark proc)))))
    (if (and p (> (point) p))
	(goto-char p)
      (call-interactively 'beginning-of-line))))