[PATCH] Include extra information in mutt version string for developer builds

[David Champion <dgc@xxxxxxxxxxxx>]

# HG changeset patch
# User David Champion <dgc@xxxxxxxxxxxx>
# Date 1284612294 18000
# Branch HEAD
# Node ID 1c6c5a4e168219a6e26ba6143cabe9f7564dfcac
# Parent  59aad6c21703484a9a298536efd4d971039d0a61
Include extra information in mutt version string for developer builds.

When a build is based on an hg clone, include extra information about
the changeset node, distance from a tagged release, and mq applied patch
count.

For example, after this patch is applied my mutt build identifies itself
(in mutt -v and in <show-version>) as:

Mutt 1.5.21+26,mq+22 (7edc2073390d) (2010-09-15)

I have applied 26 changesets applied since 1.5.21 was tagged, 22 of
which are in my mq patch series.  A 1.5.21 release build that is not
mercurial-based would still appear simply as "1.5.21".

diff -r 59aad6c21703 -r 1c6c5a4e1682 configure.ac
--- a/configure.ac      Wed Sep 15 11:47:39 2010 -0700
+++ b/configure.ac      Wed Sep 15 23:44:54 2010 -0500
@@ -7,7 +7,7 @@
 AC_INIT([mutt.h])
 AM_CONFIG_HEADER([config.h])
 
-mutt_cv_version=`cat $srcdir/VERSION`
+mutt_cv_version=`./version`
 AM_INIT_AUTOMAKE(mutt, $mutt_cv_version)
 AC_SUBST([CONFIG_STATUS_DEPENDENCIES], ['$(top_srcdir)/VERSION'])
 
diff -r 59aad6c21703 -r 1c6c5a4e1682 version
--- /dev/null   Thu Jan 01 00:00:00 1970 +0000
+++ b/version   Wed Sep 15 23:44:54 2010 -0500
@@ -0,0 +1,36 @@
+#!/bin/sh
+
+[ -d .hg ] || { cat VERSION; exit 0; }
+hg >/dev/null 2>&1 || { cat VERSION; exit 0; }
+
+# This is a mercurial repo and we have the hg command
+
+cur=$(hg id -n -r .)
+qparent=$(hg log -r qparent --template='{rev}\n' 2>/dev/null || echo $cur)
+qdelta=$(expr $cur - $qparent)
+
+# The while loop is wonky but some shells (bash) have trouble with piping
+# into "read", as with "echo 1 2 | read one two".
+hg parents --template='{latesttag} {latesttagdistance} {node|short}\n' | while 
read tag dist node; do
+       # first translate release tags into ##.##.## notation
+       case "$tag" in
+               mutt-*-rel)     tag=`echo $tag | sed -e 's/mutt-//' -e 
's/-rel//' | tr - .`;;
+       esac
+
+       # if we have nonzero distance from the latest tag, include that info
+       if [ $dist -eq 0 ]; then
+               dist=""
+       else
+               dist="+$dist"
+       fi
+
+       # if we have mq patches applied, mention it
+       if [ $qdelta -eq 0 ]; then
+               qdist=""
+       else
+               qdist=",mq+$qdelta"
+       fi
+
+       echo "$tag$dist$qdist ($node)"
+       exit 0
+done