bug#2353: 23.0.90; jka-compr: LZMA support

bug#2353: 23.0.90; jka-compr: LZMA support

[trentbuck]

From lzma(1):

    LZMA (Lempel-Ziv-Markov chain-Algorithm) is an improved version of
    famous LZ77 compression algorithm. It was improved in way of
    maximum increasing of compression ratio, keeping high
    decompression speed and low memory requirements for decompressing.

This seems to work such that foo.tar.lzma can be opened happily by
Emacs.  I suggest adding it to the default list in jka-compr.el.

    (progn
      (add-to-list 'jka-compr-compression-info-list
        ["\\.lzma\\(~\\|\\.~[0-9]+~\\)?\\'" nil "lzma"  nil nil "unlzma" nil nil t ""])
      (jka-compr-set 'jka-compr-compression-info-list jka-compr-compression-info-list))

PS: I'm not sure whether to use nil or "" for this case: there is no
reliable magic for lzma files.  From my /usr/share/file/magic:

    # URL:  http://www.7-zip.org/sdk.html
    # From: Robert Millan <rmh@aybabtu.com> and Reuben Thomas <rrt@sc3d.org>
    # Commented out because apparently not reliable (according to Debian
    # bug #364260)
    #0      string          ]\000\000\200\000       LZMA compressed data


In GNU Emacs 23.0.90.1 (i486-pc-linux-gnu, GTK+ Version 2.12.11)
 of 2009-02-07 on elegiac, modified by Debian
 (emacs-snapshot package, version 1:20090207-1)
configured using `configure  '--build' 'i486-linux-gnu' '--host' 'i486-linux-gnu' '--prefix=/usr' '--sharedstatedir=/var/lib' '--libexecdir=/usr/lib' '--localstatedir=/var' '--infodir=/usr/share/info' '--mandir=/usr/share/man' '--with-pop=yes' '--enable-locallisppath=/etc/emacs-snapshot:/etc/emacs:/usr/local/share/emacs/23.0.90/site-lisp:/usr/local/share/emacs/site-lisp:/usr/share/emacs/23.0.90/site-lisp:/usr/share/emacs/site-lisp' '--with-x=yes' '--with-x-toolkit=gtk' 'build_alias=i486-linux-gnu' 'host_alias=i486-linux-gnu' 'CFLAGS=-DDEBIAN -DSITELOAD_PURESIZE_EXTRA=5000 -g -O2' 'LDFLAGS=-g -Wl,--as-needed' 'CPPFLAGS=''

Important settings:
  value of $LC_ALL: nil
  value of $LC_COLLATE: C
  value of $LC_CTYPE: nil
  value of $LC_MESSAGES: nil
  value of $LC_MONETARY: nil
  value of $LC_NUMERIC: nil
  value of $LC_TIME: nil
  value of $LANG: en_AU.utf8
  value of $XMODIFIERS: nil
  locale-coding-system: utf-8-unix
  default-enable-multibyte-characters: t

Major mode: Emacs-Lisp

Minor modes in effect:
  diff-auto-refine-mode: t
  eldoc-mode: t
  paredit-mode: t
  shell-dirtrack-mode: t
  rcirc-track-minor-mode: t
  savehist-mode: t
  icomplete-mode: t
  partial-completion-mode: t
  show-paren-mode: t
  delete-selection-mode: t
  tooltip-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  global-auto-composition-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  column-number-mode: t
  line-number-mode: t
  transient-mark-mode: t

Recent input:
ESC x i r c C-j ESC x g n u s RET q y C-c C-@ C-c C-l 
ESC o ESC a C-c C-@ C-c C-@ C-c C-@ C-c C-@ C-c C-@ 
C-c C-@ C-x C-f ~ / V C S / C-j C-h C-s ESC O B ESC 
O B ESC > C-x C-f ~ / . e m a c s RET ESC O A ESC O 
A ESC [ 1 ~ ESC O A C-@ ESC O B ESC O B ESC O B ESC 
O B ESC w ESC x r e p o r t SPC e m a c s RET

Recent messages:
Opening nndoc server on gnus-help...done
Checking new news...done
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(No changes need to be saved)
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bug#2353: 23.0.90; jka-compr: LZMA support

[James Cloos]

When doing this, xz (lzma's replacement) should be added, too.

The typical extension is .xz and the commands are xz to compress,
unxz to decompress, and xzdec to to decompress to stdout.

Unlike lzma, xz does have reliable file magic; AFAIK, though, it
has not yet been translated into magic(5) format.

-JimC
-- 
James Cloos <cloos@jhcloos.com>         OpenPGP: 1024D/ED7DAEA6

bug#2353: 23.0.90; jka-compr: LZMA support

[Glenn Morris]

Version: 24.1

I noticed that jka-compr-compression-info-list now has entries
for lzma (since end Jan) and xz.

bug#2353: 23.0.90; jka-compr: LZMA support

[Eli Zaretskii]

> From: Glenn Morris <rgm@gnu.org>
> Date: Thu, 09 Feb 2012 16:23:22 -0500
> 
> Version: 24.1
> 
> I noticed that jka-compr-compression-info-list now has entries
> for lzma (since end Jan) and xz.

Yes, I added them (after I saw several GNU packages started using
these formats exclusively, and more are considering that).

I think we can close that bug.