From a5c56c547d024493bb90732cda20108d09392715 Mon Sep 17 00:00:00 2001
From: neilpang <neil@neilpang.com>
Date: Sat, 29 Jul 2017 15:23:31 +0800
Subject: [PATCH] minor, fix dns param

---
 acme.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/acme.sh b/acme.sh
index 38965dd..9486bcc 100755
--- a/acme.sh
+++ b/acme.sh
@@ -5440,7 +5440,7 @@ _process() {
         ;;
       --dns)
         wvalue="dns"
-        if ! _startswith "$2" "-"; then
+        if [ "$2" ] && ! _startswith "$2" "-"; then
           wvalue="$2"
           shift
         fi