From 6a23cb74c45e9f256802422d1b05162781e86930 Mon Sep 17 00:00:00 2001
From: Bruno Haible <bruno@clisp.org>
Date: Sun, 23 Mar 2008 12:18:23 +0100
Subject: [PATCH] Tweak "gnulib --version" output.

---
 ChangeLog   |  6 ++++++
 gnulib-tool | 34 +++++++++++++++++++++++++++++++---
 2 files changed, 37 insertions(+), 3 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index c34d25dee..7e2b4d626 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2008-03-23  Bruno Haible  <bruno@clisp.org>
+
+	Tweak "gnulib --version" output.
+	* gnulib-tool (func_version): Use date of last commit to ChangeLog,
+	rather than contents of ChangeLog, when possible.
+
 2008-03-21  Eric Blake  <ebb9@byu.net>
 
 	More --version tweaks.
diff --git a/gnulib-tool b/gnulib-tool
index be206e7f7..a86e4eed7 100755
--- a/gnulib-tool
+++ b/gnulib-tool
@@ -195,11 +195,39 @@ Report bugs to <bug-gnulib@gnu.org>."
 func_version ()
 {
   func_gnulib_dir
-  date=`sed 's/ .*//;q' "$gnulib_dir"/ChangeLog`
-  version=`"$gnulib_dir"/build-aux/git-version-gen /dev/null`
+  if test -d "$gnulib_dir"/.git \
+     && (git --version) >/dev/null 2>/dev/null \
+     && (date --version) >/dev/null 2>/dev/null; then
+    # gnulib checked out from git.
+    sed_extract_first_date='/^Date/{
+s/^Date:[	 ]*//p
+q
+}'
+    date=`cd "$gnulib_dir" && git log ChangeLog | sed -n -e "$sed_extract_first_date"`
+    # Turn "Fri Mar 21 07:16:51 2008 -0600" into "Mar 21 2008 07:16:51 -0600".
+    sed_year_before_time='s/^[^ ]* \([^ ]*\) \([0-9]*\) \([0-9:]*\) \([0-9]*\) /\1 \2 \4 \3 /'
+    date=`echo "$date" | sed -e "$sed_year_before_time"`
+    # Use GNU date to compute the time in GMT.
+    date=`date -d "$date" -u +"%Y-%m-%d %H:%M:%S"`
+    version=' '`"$gnulib_dir"/build-aux/git-version-gen /dev/null`
+  else
+    if test -d "$gnulib_dir"/CVS \
+       && (cvs --version) >/dev/null 2>/dev/null; then
+      # gnulib checked out from CVS.
+      sed_extract_first_date='/^date: /{
+s/^date: \([0-9][0-9][0-9][0-9]\).\([0-9][0-9]\).\([0-9][0-9]\) \([0-9][0-9]:[0-9][0-9]:[0-9][0-9]\).*/\1-\2-\3 \4/p
+q
+}'
+      date=`cd "$gnulib_dir" && cvs log -N ChangeLog 2>/dev/null | sed -n -e "$sed_extract_first_date"`
+    else
+      # gnulib copy without versioning information.
+      date=`sed -e 's/ .*//;q' "$gnulib_dir"/ChangeLog`
+    fi
+    version=
+  fi
   year=`"$gnulib_dir"/build-aux/mdate-sh "$self_abspathname" | sed 's,^.* ,,'`
   echo "\
-gnulib-tool (GNU $package $date) $version
+gnulib-tool (GNU $package $date)$version
 Copyright (C) $year Free Software Foundation, Inc.
 License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
 This is free software: you are free to change and redistribute it.
-- 
2.11.0