diff --git a/build-aux/git-version-gen b/build-aux/git-version-gen
index c278f6a..8a238b0 100755
--- a/build-aux/git-version-gen
+++ b/build-aux/git-version-gen
@@ -1,6 +1,6 @@
 #!/bin/sh
 # Print a version string.
-scriptversion=2010-10-13.20; # UTC
+scriptversion=2011-01-03.00; # UTC
 
 # Copyright (C) 2007-2011 Free Software Foundation, Inc.
 #
@@ -78,76 +78,96 @@ tag_sed_script="${2:-s/x/x/}"
 nl='
 '
 
-# Avoid meddling by environment variable of the same name.
-v=
+get_ver()
+{
+    local PS4='>gv> '
+    git status >/dev/null 2>&1 || {
+        printf UNKNOWN
+        exit 0
+    }
 
-# 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
-    case $v in
-	*$nl*) v= ;; # reject multi-line output
-	[0-9]*) ;;
-	*) v= ;;
+    test "`git log -1 --pretty=format:x . 2>&1`" = x || {
+        printf UNKNOWN
+        exit 0
+    }
+
+    X=`git describe --abbrev=4 --match='v*' HEAD || \
+        git describe --abbrev=4 HEAD` || {
+        printf UNKNOWN
+        exit 0
+    }
+
+    case "$X" in
+    v[0-9]* ) : ;;
+    * )
+        printf UNKNOWN
+        exit 0
+        ;;
     esac
-    test -z "$v" \
-	&& echo "$0: WARNING: $tarball_version_file seems to be damaged" 1>&2
-fi
 
-if test -n "$v"
-then
-    : # use $v
-# Otherwise, if there is at least one git commit involving the working
-# directory, and "git describe" output looks sensible, use that to
-# derive a version string.
-elif test "`git log -1 --pretty=format:x . 2>&1`" = x \
-    && v=`git describe --abbrev=4 --match='v*' HEAD 2>/dev/null \
-	  || git describe --abbrev=4 HEAD 2>/dev/null` \
-    && v=`printf '%s\n' "$v" | sed "$tag_sed_script"` \
-    && case $v in
-	 v[0-9]*) ;;
-	 *) (exit 1) ;;
-       esac
-then
     # Is this a new git that lists number of commits since the last
     # tag or the previous older version that did not?
     #   Newer: v6.10-77-g0f8faeb
     #   Older: v6.10-g0f8faeb
-    case $v in
+    case $X in
 	*-*-*) : git describe is okay three part flavor ;;
 	*-*)
 	    : git describe is older two part flavor
 	    # Recreate the number of commits and rewrite such that the
 	    # result is the same as if we were using the newer version
 	    # of git describe.
-	    vtag=`echo "$v" | sed 's/-.*//'`
+	    vtag=`echo "$X" | sed 's/-.*//'`
 	    numcommits=`git rev-list "$vtag"..HEAD | wc -l`
-	    v=`echo "$v" | sed "s/\(.*\)-\(.*\)/\1-$numcommits-\2/"`;
+	    X=`echo "$X" | sed "s/\(.*\)-\(.*\)/\1-$numcommits-\2/"`;
 	    ;;
     esac
 
+    # Don't declare a version "dirty" merely because a time stamp has changed.
+    silent_git update-index --refresh >/dev/null 2>&1
+
+    dirty=`git diff-index --name-only HEAD` || dirty=
+    case "$dirty" in
+    '') ;;
+    *) # Append the suffix only if there isn't one already.
+	case $X in
+	  *-dirty) ;;
+	  *) X="$X-dirty" ;;
+	esac
+        ;;
+    esac
+
     # Change the first '-' to a '.', so version-comparing tools work properly.
     # Remove the "g" in git describe's output string, to save a byte.
-    v=`echo "$v" | sed 's/-/./;s/\(.*\)-g/\1-/'`;
+    echo "$X" | sed 's/^v//;s/-/./;s/\(.*\)-g/\1-/'
+}
+
+# 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
+    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
 else
-    v=UNKNOWN
+    v=
 fi
 
-v=`echo "$v" |sed 's/^v//'`
-
-# Don't declare a version "dirty" merely because a time stamp has changed.
-git update-index --refresh > /dev/null 2>&1
+if test -n "$v"
+then
+    : # use $v
 
-dirty=`sh -c 'git diff-index --name-only HEAD' 2>/dev/null` || dirty=
-case "$dirty" in
-    '') ;;
-    *) # Append the suffix only if there isn't one already.
-	case $v in
-	  *-dirty) ;;
-	  *) v="$v-dirty" ;;
-	esac ;;
-esac
+else
+    # 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.
+    #
+    v=`get_ver` 2>/dev/null
+fi
 
 # Omit the trailing newline, so that m4_esyscmd can use the result directly.
 echo "$v" | tr -d "$nl"