Handle getconf returning "undefined".

* m4/libtool.m4: Check for "undefined" from `getconf`.

diff --git a/m4/libtool.m4 b/m4/libtool.m4
index cb8c4a4ff42881aa25acb0d23120b974fadeb0eb..e8c8911533a9be8d0f14a93b23e8392f4659d304 100644 (file)
--- a/m4/libtool.m4
+++ b/m4/libtool.m4
@@ -1692,7 +1692,8 @@ AC_CACHE_VAL([lt_cv_sys_max_cmd_len], [dnl
     ;;
   *)
     lt_cv_sys_max_cmd_len=`(getconf ARG_MAX) 2> /dev/null`
-    if test -n "$lt_cv_sys_max_cmd_len"; then
+    if test -n "$lt_cv_sys_max_cmd_len" && \
+       test undefined != "$lt_cv_sys_max_cmd_len"; then
       lt_cv_sys_max_cmd_len=`expr $lt_cv_sys_max_cmd_len \/ 4`
       lt_cv_sys_max_cmd_len=`expr $lt_cv_sys_max_cmd_len \* 3`
     else