examples/udhcp: do not rewrite resolv.conf if no DNS servers. Closes 6788

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

2 files changed, 22 insertions, 14 deletions

diff --git a/examples/udhcp/sample.bound b/examples/udhcp/sample.bound
index bd3569c77..7c9d857e0 100755
--- a/examples/udhcp/sample.bound
+++ b/examples/udhcp/sample.bound
@@ -22,10 +22,14 @@ then
         done
 fi
 
-echo -n > $RESOLV_CONF
-[ -n "$domain" ] && echo domain $domain >> $RESOLV_CONF
-for i in $dns
-do
-        echo adding dns $i
-        echo nameserver $i >> $RESOLV_CONF
-done
+# Only replace resolv.conf is we have at least one DNS server
+if [ -n "$dns" ]
+then
+        echo -n > $RESOLV_CONF
+        [ -n "$domain" ] && echo domain $domain >> $RESOLV_CONF
+        for i in $dns
+        do
+                echo adding dns $i
+                echo nameserver $i >> $RESOLV_CONF
+        done
+fi
diff --git a/examples/udhcp/sample.renew b/examples/udhcp/sample.renew
index ea368fc9e..4dce8486a 100755
--- a/examples/udhcp/sample.renew
+++ b/examples/udhcp/sample.renew
@@ -22,10 +22,14 @@ then
         done
 fi
 
-echo -n > $RESOLV_CONF
-[ -n "$domain" ] && echo domain $domain >> $RESOLV_CONF
-for i in $dns
-do
-        echo adding dns $i
-        echo nameserver $i >> $RESOLV_CONF
-done
+# Only replace resolv.conf is we have at least one DNS server
+if [ -n "$dns" ]
+then
+        echo -n > $RESOLV_CONF
+        [ -n "$domain" ] && echo domain $domain >> $RESOLV_CONF
+        for i in $dns
+        do
+                echo adding dns $i
+                echo nameserver $i >> $RESOLV_CONF
+        done
+fi