Merge "StaticIpConfiguration: Couple of minor fixes"
diff --git a/core/java/android/net/StaticIpConfiguration.java b/core/java/android/net/StaticIpConfiguration.java
index 5bc9953..990c114 100644
--- a/core/java/android/net/StaticIpConfiguration.java
+++ b/core/java/android/net/StaticIpConfiguration.java
@@ -25,6 +25,8 @@
 import android.os.Parcel;
 import android.os.Parcelable;
 
+import com.android.internal.util.Preconditions;
+
 import java.net.InetAddress;
 import java.util.ArrayList;
 import java.util.List;
@@ -152,6 +154,7 @@
          * @return The {@link Builder} for chaining.
          */
         public @NonNull Builder setDnsServers(@NonNull Iterable<InetAddress> dnsServers) {
+            Preconditions.checkNotNull(dnsServers);
             mDnsServers = dnsServers;
             return this;
         }
@@ -175,8 +178,10 @@
             final StaticIpConfiguration config = new StaticIpConfiguration();
             config.ipAddress = mIpAddress;
             config.gateway = mGateway;
-            for (InetAddress server : mDnsServers) {
-                config.dnsServers.add(server);
+            if (mDnsServers != null) {
+                for (InetAddress server : mDnsServers) {
+                    config.dnsServers.add(server);
+                }
             }
             config.domains = mDomains;
             return config;