+# Note this deviates from the version comparison in automake
+# in that it treats 1.5 < 1.5.0, and treats 1.4.4a < 1.4-p3a
+# but this should suffice as we won't be specifying old
+# version formats or redundant trailing .0 in bootstrap.conf.
+# If we did want full compatibility then we should probably
+# use m4_version_compare from autoconf.
+sort_ver() { # sort -V is not generally available
+ ver1="$1"
+ ver2="$2"
+
+ # split on '.' and compare each component
+ i=1
+ while : ; do
+ p1=$(echo "$ver1" | cut -d. -f$i)
+ p2=$(echo "$ver2" | cut -d. -f$i)
+ if [ ! "$p1" ]; then
+ echo "$1 $2"
+ break
+ elif [ ! "$p2" ]; then
+ echo "$2 $1"
+ break
+ elif [ ! "$p1" = "$p2" ]; then
+ if [ "$p1" -gt "$p2" ] 2>/dev/null; then # numeric comparison
+ echo "$2 $1"
+ elif [ "$p2" -gt "$p1" ] 2>/dev/null; then # numeric comparison
+ echo "$1 $2"
+ else # numeric, then lexicographic comparison
+ lp=$(printf "$p1\n$p2\n" | LANG=C sort -n | tail -n1)
+ if [ "$lp" = "$p2" ]; then
+ echo "$1 $2"
+ else
+ echo "$2 $1"
+ fi
+ fi
+ break
+ fi
+ i=$(($i+1))
+ done
+}