Fix image-mode-fit-frame resizing

* lisp/image-mode.el (image-mode-fit-frame): Use pixel sizes
instead of lines/columns to get more accurate resizing (bug#37630).

1 files changed, 17 insertions, 15 deletions

diff --git a/lisp/image-mode.el b/lisp/image-mode.el
index 38a5e7cdfdc..863d014cdc4 100644
--- a/lisp/image-mode.el
+++ b/lisp/image-mode.el
@@ -420,37 +420,39 @@ call."
   (interactive (list nil t))
   (let* ((buffer (current-buffer))
          (display (image-get-display-property))
-         (size (image-display-size display))
+         (size (image-display-size display t))
 	 (saved (frame-parameter frame 'image-mode-saved-params))
 	 (window-configuration (current-window-configuration frame))
-	 (width  (frame-width  frame))
-	 (height (frame-height frame)))
+	 (frame-width (frame-pixel-width frame))
+	 (frame-height (frame-pixel-height frame)))
     (with-selected-frame (or frame (selected-frame))
       (if (and toggle saved
-	       (= (caar saved) width)
-	       (= (cdar saved) height))
+	       (= (caar saved) frame-width)
+	       (= (cdar saved) frame-height))
 	  (progn
-	    (set-frame-width  frame (car (nth 1 saved)))
-	    (set-frame-height frame (cdr (nth 1 saved)))
+	    (set-frame-width frame (car (nth 1 saved)) nil t)
+	    (set-frame-height frame (cdr (nth 1 saved)) nil t)
 	    (set-window-configuration (nth 2 saved))
 	    (set-frame-parameter frame 'image-mode-saved-params nil))
 	(delete-other-windows)
 	(switch-to-buffer buffer t t)
-	(let* ((edges (window-inside-edges))
-	       (inner-width  (- (nth 2 edges) (nth 0 edges)))
+	(let* ((edges (window-inside-pixel-edges))
+	       (inner-width (- (nth 2 edges) (nth 0 edges)))
 	       (inner-height (- (nth 3 edges) (nth 1 edges))))
-	  (set-frame-width  frame (+ (ceiling (car size))
-				     width (- inner-width)))
+	  (set-frame-width frame (+ (ceiling (car size))
+				    (- frame-width inner-width))
+                           nil t)
 	  (set-frame-height frame (+ (ceiling (cdr size))
-				     height (- inner-height)))
+				     (- frame-height inner-height))
+                            nil t)
 	  ;; The frame size after the above `set-frame-*' calls may
 	  ;; differ from what we specified, due to window manager
 	  ;; interference.  We have to call `frame-width' and
 	  ;; `frame-height' to get the actual results.
 	  (set-frame-parameter frame 'image-mode-saved-params
-			       (list (cons (frame-width)
-					   (frame-height))
-				     (cons width height)
+			       (list (cons (frame-pixel-width frame)
+					   (frame-pixel-height frame))
+				     (cons frame-width frame-height)
 				     window-configuration)))))))
 
 ;;; Image Mode setup