MS-Windows follow-up to 2013-10-10T01:03:11Z!rgm@gnu.org: support giflib 5.x.

 src/image.c (GIFLIB_MAJOR): Define to 4 if undefined.
 (GIFLIB_MINOR, GIFLIB_RELEASE): Define to zero if undefined.
 (GifErrorString) [GIFLIB_MAJOR >= 5]: Define a function pointer.
 (gif_load): For giflib v5.x and later, display the error message
 produced by giflib when its functions fail.
 (syms_of_image) <Qlibgif_version> [HAVE_NTGUI]: New DEFSYM.

 lisp/term/w32-win.el (dynamic-library-alist): Define separate lists
 of GIF DLLs for versions before and after 5.0.0 of giflib.

Fixes: debbugs:15531

2 files changed, 19 insertions, 1 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index bb675ce5088..a06055ddb9b 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,9 @@
+2013-10-10  Eli Zaretskii  <eliz@gnu.org>
+
+        * term/w32-win.el (dynamic-library-alist): Define separate lists
+        of GIF DLLs for versions before and after 5.0.0 of giflib.
+        (Bug#15531)
+
 2013-10-10  João Távora <joaotavora@gmail.com>
 
         * vc/vc.el (vc-diff-build-argument-list-internal): If the file is
diff --git a/lisp/term/w32-win.el b/lisp/term/w32-win.el
index 892ac9749d6..9690a5a7d75 100644
--- a/lisp/term/w32-win.el
+++ b/lisp/term/w32-win.el
@@ -223,7 +223,19 @@ See the documentation of `create-fontset-from-fontset-spec' for the format.")
                "libpng13d.dll" "libpng13.dll"))
        '(jpeg "jpeg62.dll" "libjpeg.dll" "jpeg-62.dll" "jpeg.dll")
        '(tiff "libtiff3.dll" "libtiff.dll")
-       '(gif "giflib4.dll" "libungif4.dll" "libungif.dll")
+       ;; Versions of giflib 5.0.0 and later changed signatures of
+       ;; several functions used by Emacs, which makes those versions
+       ;; incompatible with previous ones.  We select the correct
+       ;; libraries according to the version of giflib we were
+       ;; compiled against.  (If we were compiled without GIF support,
+       ;; libgif-version's value is -1.)
+       (if (>= libgif-version 50000)
+           ;; Yes, giflib 5.x uses 6 as the major version of the API,
+           ;; thus "libgif-6.dll" below (giflib 4.x used 5 as the
+           ;; major API version).
+           ;; giflib5.dll is from the lua-files project.
+           '(gif "libgif-6.dll" "giflib5.dll")
+         '(gif "libgif-5.dll" "giflib4.dll" "libungif4.dll" "libungif.dll"))
        '(svg "librsvg-2-2.dll")
        '(gdk-pixbuf "libgdk_pixbuf-2.0-0.dll")
        '(glib "libglib-2.0-0.dll")