Since goto-char signals an error when given a marker pointing to a buffer
other than the current one (probably to prevent programming errors) and
pop-global-mark only works on the global-mark-ring, there is a need for a
simple function that jumps to the location of an arbitrary marker.  The
following function does that and is based on pop-global-mark.  Please
consider adding it to simple.el.

Bob

(defun goto-marker (marker)
  "Make MARKER's buffer and position current."
  (interactive)
  (cond ((not (markerp marker))
(error "Invalid marker: %s" marker))
((not (marker-buffer marker))
(error "Invalid marker buffer: %s" marker))
(t (let* ((buffer (marker-buffer marker))
 (position (marker-position marker)))
    (set-buffer buffer)
    (or (and (>= position (point-min))
     (<= position (point-max)))
(if widen-automatically
    (widen)
  (error "Marker position is outside accessible part of buffer: %s"
marker)))
    (goto-char position)
    (switch-to-buffer buffer)))))