git-version-gen: include command name in one more diagnostic

[gnulib.git] / build-aux / git-version-gen

diff --git a/build-aux/git-version-gen b/build-aux/git-version-gen
index 5a7e989..c337673 100755 (executable)
--- a/build-aux/git-version-gen
+++ b/build-aux/git-version-gen
@@ -1,8 +1,8 @@
 #!/bin/sh
 # Print a version string.
-scriptversion=2010-04-26.16; # UTC
+scriptversion=2011-01-03.10; # UTC
 
-# Copyright (C) 2007-2010 Free Software Foundation, Inc.
+# Copyright (C) 2007-2011 Free Software Foundation, Inc.
 #
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -67,34 +67,44 @@ scriptversion=2010-04-26.16; # UTC
 #      echo $(VERSION) > $(distdir)/.tarball-version
 
 case $# in
-    1) ;;
-    *) echo 1>&2 "Usage: $0 \$srcdir/.tarball-version"; exit 1;;
+    1|2) ;;
+    *) echo 1>&2 "Usage: $0 \$srcdir/.tarball-version" \
+         '[TAG-NORMALIZATION-SED-SCRIPT]'
+       exit 1;;
 esac
 
 tarball_version_file=$1
+tag_sed_script="${2:-s/x/x/}"
 nl='
 '
 
+# Avoid meddling by environment variable of the same name.
+v=
+
 # First see if there is a tarball-only version file.
 # then try "git describe", then default.
 if test -f $tarball_version_file
 then
-    v=`cat $tarball_version_file` || exit 1
+    v=`cat $tarball_version_file` || v=
     case $v in
        *$nl*) v= ;; # reject multi-line output
        [0-9]*) ;;
        *) v= ;;
     esac
     test -z "$v" \
-       && echo "$0: WARNING: $tarball_version_file seems to be damaged" 1>&2
+       && echo "$0: WARNING: $tarball_version_file is missing or damaged" 1>&2
 fi
 
 if test -n "$v"
 then
     : # use $v
-elif test -d .git \
+# Otherwise, if there is at least one git commit involving the working
+# directory, and "git describe" output looks sensible, use that to
+# derive a version string.
+elif test "`git log -1 --pretty=format:x . 2>&1`" = x \
     && v=`git describe --abbrev=4 --match='v*' HEAD 2>/dev/null \
          || git describe --abbrev=4 HEAD 2>/dev/null` \
+    && v=`printf '%s\n' "$v" | sed "$tag_sed_script"` \
     && case $v in
         v[0-9]*) ;;
         *) (exit 1) ;;