The image does not refresh even if it has been modified. The test below
opens an image in emacs, then swaps the image with a second (different)
image, before re-opening the first, now modified, image. Even after
refreshing the buffer with g, the image still looks like the original
image instead of the new one.

Sam

(defun img-bug ()
  (interactive)
  (let ((img1 "test1.png")
	(img2 "test2.png")
	(tmp  "tmp.png"))
    (find-file img1)
    ;; swap the two images by renaming them
    (copy-file img1 tmp t)
    (copy-file img2 img1 t)
    (copy-file tmp img2 t)
    (find-file img1)))





In GNU Emacs 24.4.1 (x86_64-apple-darwin13.4.0, NS apple-appkit-1265.21)
 of 2014-10-20 on builder10-9.porkrind.org
Windowing system distributor `Apple', version 10.3.1348
Configured using:
 `configure --with-ns'

Important settings:
  value of $LC_ALL: en_GB.UTF-8
  value of $LANG: en_GB.UTF-8
  locale-coding-system: utf-8-unix

Major mode: Dired

Minor modes in effect:
  shell-dirtrack-mode: t
  tooltip-mode: t
  electric-indent-mode: t
  mouse-wheel-mode: t
  tool-bar-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  blink-cursor-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  buffer-read-only: t
  line-number-mode: t
  transient-mark-mode: t

Recent input:
n <return> s-k s-o <down-mouse-1> <mouse-1> C-x b <return> 
C-x b t m <tab> C-g C-x b * <tab> <backspace> / <tab> 
t <tab> C-g C-x C-f / t m <tab> <return> C-n C-n C-n 
s C-p C-p C-p C-p C-p C-p C-p C-p C-n C-p C-p C-p C-p 
C-p C-p C-p C-p C-p <return> q C-n <return> q C-p <return> 
n p n p g y e s <return> q & o p e n <return> q <backspace> 
C-x k <return> C-n & o p e n <return> C-p & p e n <return> 
<help-echo> <down-mouse-1> <mouse-1> <help-echo> <down-mouse-1> 
<mouse-1> <help-echo> <help-echo> <help-echo> <down-mouse-1> 
<mouse-1> & o p e n <return> <down-mouse-1> <mouse-1> 
s-o <down-mouse-1> <mouse-1> s-x s-x C-g C-g s-x C-x 
C-q s-x C-g C-g C-g s-x M-x i m g - b u <tab> <return> 
y e s <return> <help-echo> <down-mouse-1> <mouse-1> 
C-x b <return> g g g g s-r <backspace> <backspace> 
<backspace> <backspace> C-c C-c s-o <down-mouse-1> 
<mouse-1> C-x b s c <tab> <return> C-p C-p C-p C-p 
C-p C-p <help-echo> <help-echo> <down-mouse-1> <mouse-1> 
g C-p C-p C-p & o p e n <tab> <return> q <backspace> 
C-x b <return> C-n & o p e n <return> q <backspace> 
C-x k <return> C-p <return> q C-n <return> g y e s 
<return> q s-o <down-mouse-1> <mouse-1> s-k s-k C-x 
b s c <tab> r <tab> C-g <help-echo> C-x 1 M-x i m g 
- b u <tab> <return> y e s <return> n y e s <return> 
p n p q M-x e m a c s - r e <tab> <backspace> <backspace> 
r e p <tab> <backspace> <backspace> <backspace> b u 
<tab> <backspace> <backspace> r e <tab> <backspace> 
<backspace> <backspace> <backspace> <backspace> <backspace> 
<backspace> <backspace> r e <tab> p <tab> o <tab> r 
<tab> <return>

Recent messages:
Type C-c C-c to view the image as text.
s-r is undefined
(No changes to be performed)
open test1.png: finished.
open test2.png: finished.
Type C-c C-c to view the image as text. [2 times]
Quit
Type C-c C-c to view the image as text. [6 times]
Making completion list... [3 times]
<s-backspace> is undefined [2 times]

Load-path shadows:
None found.

Features:
(shadow sort gnus-util mail-extr emacsbug message format-spec rfc822 mml
mml-sec mm-decode mm-bodies mm-encode mail-parse rfc2231 mailabbrev
gmm-utils mailheader sendmail rfc2047 rfc2045 ietf-drums mm-util
help-fns mail-prsvr mail-utils wdired image-file help-mode shell
pcomplete comint ansi-color ring dired-aux image-mode easymenu dired
time-date tooltip electric uniquify ediff-hook vc-hooks lisp-float-type
mwheel ns-win tool-bar dnd fontset image regexp-opt fringe
tabulated-list newcomment lisp-mode prog-mode register page menu-bar
rfn-eshadow timer select scroll-bar mouse jit-lock font-lock syntax
facemenu font-core frame cham georgian utf-8-lang misc-lang vietnamese
tibetan thai tai-viet lao korean japanese hebrew greek romanian slovak
czech european ethiopic indian cyrillic chinese case-table epa-hook
jka-cmpr-hook help simple abbrev minibuffer nadvice loaddefs button
faces cus-face macroexp files text-properties overlay sha1 md5 base64
format env code-pages mule custom widget hashtable-print-readable
backquote make-network-process cocoa ns multi-tty emacs)

Memory information:
((conses 16 86277 6089)
 (symbols 48 18474 0)
 (miscs 40 67 263)
 (strings 32 13539 4255)
 (string-bytes 1 371069)
 (vectors 16 10540)
 (vector-slots 8 388683 5690)
 (floats 8 65 354)
 (intervals 56 575 22)
 (buffers 960 14))