+(defcustom fit-frame-to-buffer nil
+ "Non-nil means `fit-window-to-buffer' can resize frames.
+A frame can be resized if and only if its root window is a live
+window. The height of the root window is subject to the values
+of `fit-frame-to-buffer-max-height' and `window-min-height'."
+ :type 'boolean
+ :version "24.2"
+ :group 'help)
+
+(defcustom fit-frame-to-buffer-bottom-margin 4
+ "Bottom margin for `fit-frame-to-buffer'.
+This is the number of lines `fit-frame-to-buffer' leaves free at the
+bottom of the display in order to not obscure the system task bar."
+ :type 'integer
+ :version "24.2"
+ :group 'windows)
+
+(defun fit-frame-to-buffer (&optional frame max-height min-height)
+ "Adjust height of FRAME to display its buffer's contents exactly.
+FRAME can be any live frame and defaults to the selected one.
+
+Optional argument MAX-HEIGHT specifies the maximum height of
+FRAME and defaults to the height of the display below the current
+top line of FRAME minus FIT-FRAME-TO-BUFFER-BOTTOM-MARGIN.
+Optional argument MIN-HEIGHT specifies the minimum height of
+FRAME."
+ (interactive)
+ (setq frame (window-normalize-frame frame))
+ (let* ((root (frame-root-window frame))
+ (frame-min-height
+ (+ (- (frame-height frame) (window-total-size root))
+ window-min-height))
+ (frame-top (frame-parameter frame 'top))
+ (top (if (consp frame-top)
+ (funcall (car frame-top) (cadr frame-top))
+ frame-top))
+ (frame-max-height
+ (- (/ (- (x-display-pixel-height frame) top)
+ (frame-char-height frame))
+ fit-frame-to-buffer-bottom-margin))
+ (compensate 0)
+ delta)
+ (when (and (window-live-p root) (not (window-size-fixed-p root)))
+ (with-selected-window root
+ (cond
+ ((not max-height)
+ (setq max-height frame-max-height))
+ ((numberp max-height)
+ (setq max-height (min max-height frame-max-height)))
+ (t
+ (error "%s is an invalid maximum height" max-height)))
+ (cond
+ ((not min-height)
+ (setq min-height frame-min-height))
+ ((numberp min-height)
+ (setq min-height (min min-height frame-min-height)))
+ (t
+ (error "%s is an invalid minimum height" min-height)))
+ ;; When tool-bar-mode is enabled and we have just created a new
+ ;; frame, reserve lines for toolbar resizing. This is needed
+ ;; because for reasons unknown to me Emacs (1) reserves one line
+ ;; for the toolbar when making the initial frame and toolbars
+ ;; are enabled, and (2) later adds the remaining lines needed.
+ ;; Our code runs IN BETWEEN (1) and (2). YMMV when you're on a
+ ;; system that behaves differently.
+ (let ((quit-restore (window-parameter root 'quit-restore))
+ (lines (tool-bar-lines-needed frame)))
+ (when (and quit-restore (eq (car quit-restore) 'frame)
+ (not (zerop lines)))
+ (setq compensate (1- lines))))
+ (message "%s" compensate)
+ (setq delta
+ ;; Always count a final newline - we don't do any
+ ;; post-processing, so let's play safe.
+ (+ (count-screen-lines nil nil t)
+ (- (window-body-size))
+ compensate)))
+ ;; Move away from final newline.
+ (when (and (eobp) (bolp) (not (bobp)))
+ (set-window-point root (line-beginning-position 0)))
+ (set-window-start root (point-min))
+ (set-window-vscroll root 0)
+ (condition-case nil
+ (set-frame-height
+ frame
+ (min (max (+ (frame-height frame) delta)
+ min-height)
+ max-height))
+ (error (setq delta nil))))
+ delta))
+