m4/mdw-libtool-version-info.m4: Don't try to parse `UNKNOWN' token.

diff --git a/m4/mdw-libtool-version-info.m4 b/m4/mdw-libtool-version-info.m4
index a4932b2351ebc00181b8ff5853c81c90e2f9c63c..109603f148d264ca3fbc12bc197064c65acda5ee 100644 (file)
--- a/m4/mdw-libtool-version-info.m4
+++ b/m4/mdw-libtool-version-info.m4
@@ -42,7 +42,14 @@ dnl -*-autoconf-*-
 
 # serial 1
 AC_DEFUN([mdw_LIBTOOL_VERSION_INFO],
-[set -- $(echo $PACKAGE_VERSION |
-           sed 's:[^\([0-9][0-9]*\)\.\([0-9][0-9]*\)\.\([0-9][0-9]*\).*$]:\1 \2 \3:')
+[case $PACKAGE_VERSION in
+  UNKNOWN)
+    set -- 0 0 0
+    ;;
+  *)
+    num="\(@<:@0-9@:>@@<:@0-9@:>@*\)"
+    set -- $(echo $PACKAGE_VERSION | sed "s:^$num\.$num\.$num.*\$:\1 \2 \3:")
+    ;;
+esac
 LIBTOOL_VERSION_INFO="$(expr $[]1 + $[]2):$[]3:$[]2"
 AC_SUBST([LIBTOOL_VERSION_INFO])])