bug#13770: 24.3.50; Add support for .txz suffix, XZ-compressed tar archives

[Ulrich Müller]

The .txz suffix has recently become somewhat popular. For example,
Slackware GNU/Linux and FreeBSD are using it.

Attached patch adds support for .txz to jka-compr. (In other places,
like dired-x, .txz is already recognised). It would be nice if this
could be added to the trunk.

2013-02-20  Ulrich Müller  <ulm@gentoo.org>

        * jka-cmpr-hook.el (jka-compr-compression-info-list)
        (jka-compr-mode-alist-additions): Handle .txz suffix for
        XZ-compressed tar archives.

--- emacs/lisp/jka-cmpr-hook.el
+++ emacs/lisp/jka-cmpr-hook.el
@@ -234,6 +234,10 @@
      "XZ compressing"     "xz"           ("-c" "-q")
      "XZ uncompressing"   "xz"           ("-c" "-q" "-d")
      t t "\3757zXZ\0"]
+    ["\\.txz\\'"
+     "XZ compressing"     "xz"           ("-c" "-q")
+     "XZ uncompressing"   "xz"           ("-c" "-q" "-d")
+     t nil "\3757zXZ\0"]
     ;; dzip is gzip with random access.  Its compression program can't
     ;; read/write stdin/out, so .dz files can only be viewed without
     ;; saving, having their contents decompressed with gzip.
@@ -302,7 +306,9 @@
   :group 'jka-compr)
 
 (defcustom jka-compr-mode-alist-additions
-  (list (cons (purecopy "\\.tgz\\'") 'tar-mode) (cons (purecopy "\\.tbz2?\\'") 
'tar-mode))
+  (list (cons (purecopy "\\.tgz\\'") 'tar-mode)
+       (cons (purecopy "\\.tbz2?\\'") 'tar-mode)
+       (cons (purecopy "\\.txz\\'") 'tar-mode))
   "List of pairs added to `auto-mode-alist' when installing jka-compr.
 Uninstalling jka-compr removes all pairs from `auto-mode-alist' that
 installing added.