[PATCH] maint: RFC: add lzip tarballs

[Eric Blake]

Coreutils picked 'dist-xz' back in 2008 (see commit b52a8860),
and automake didn't support 'dist-lzip' until 2011 (but forgot
to mention it in NEWS).  Our choice of .xz has thus been mostly
one of inertia.

But these days, there are strong arguments for including .lzip
distributions, either in addition or in place of .xz:
http://www.nongnu.org/lzip/xz_inadequate.html

For now, take the conservative approach by adding rather replacing
the .xz distribution format.

* configure.ac (AM_INIT_AUTOMAKE): Add dist-lzip.
* README-prereq: Document lzip.
---

RFC because I can't (quickly) find a git repository for lzip;
savannah still has only a CVS checkout.

Depending on how the conversation goes here, I plan on doing the
same for autoconf 2.70 (which I'm still hoping to release soon,
although I missed my goal of doing it in 2016).

 README-prereq | 8 ++++++--
 configure.ac  | 4 ++--
 2 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/README-prereq b/README-prereq
index 099fc01..501aa96 100644
--- a/README-prereq
+++ b/README-prereq
@@ -49,9 +49,9 @@ set correctly by running this command:
   ./configure --prefix=$prefix
   make install

-This package uses XZ utils (successor to LZMA) to create
+This package uses XZ utils (successor to LZMA) and LXIP to create
 a compressed distribution tarball.  Using this feature of Automake
-requires version 1.10a or newer, as well as the xz program itself.
+requires version 1.11.2 or newer, as well as the xz and lzip programs.

 * xz *

@@ -61,4 +61,8 @@ requires version 1.10a or newer, as well as the xz program 
itself.
   ./configure --prefix=$prefix
   make install

+* lzip *
+
+  https://savannah.nongnu.org/cvs/?group=lzip
+
 Now you can build this package as described in README-hacking.
diff --git a/configure.ac b/configure.ac
index b009a90..23b1b8c 100644
--- a/configure.ac
+++ b/configure.ac
@@ -32,8 +32,8 @@ AC_CONFIG_SRCDIR([src/ls.c])
 AC_CONFIG_AUX_DIR([build-aux])
 AC_CONFIG_HEADERS([lib/config.h:lib/config.hin])

-AM_INIT_AUTOMAKE([1.11.2 no-dist-gzip dist-xz color-tests parallel-tests
-                  subdir-objects])
+AM_INIT_AUTOMAKE([1.11.2 no-dist-gzip dist-xz dist-lzip color-tests
+                  parallel-tests subdir-objects])
 AM_SILENT_RULES([yes]) # make --enable-silent-rules the default.

 dnl POSIXCHECK is worthwhile for maintainers, but adds several seconds
-- 
2.9.3