fix issue #642

src/main/java/redis/clients/jedis/JedisSentinelPool.java

@@ -130,10 +130,17 @@ public class JedisSentinelPool extends Pool<Jedis> {
 
 				try {
 					Jedis jedis = new Jedis(hap.getHost(), hap.getPort());
-
 					if (master == null) {
-						master = toHostAndPort(jedis
+						List<String> masterAddr = jedis
-								.sentinelGetMasterAddrByName(masterName));
+								.sentinelGetMasterAddrByName(masterName);
+						if (masterAddr == null || masterAddr.size() != 2) {
+							log.warning("Can not get master addr, master name: "
+									+ masterName + ". Sentinel: " + hap + ".");
+							jedis.disconnect();
+							continue;
+						}
+
+						master = toHostAndPort(masterAddr);
 						log.fine("Found Redis master at " + master);
 						jedis.disconnect();
 						break outer;

src/test/java/redis/clients/jedis/tests/JedisSentinelPoolTest.java

@@ -2,6 +2,7 @@ package redis.clients.jedis.tests;
 
 import java.util.HashSet;
 import java.util.Set;
+import java.util.concurrent.TimeUnit;
 
 import org.apache.commons.pool2.impl.GenericObjectPoolConfig;
 import org.junit.Before;
@@ -35,6 +36,29 @@ public class JedisSentinelPoolTest extends JedisTestBase {
 		sentinelJedis1 = new Jedis(sentinel1.getHost(), sentinel1.getPort());
 	}
 
+	@Test
+	public void errorMasterNameNotThrowException() throws InterruptedException {
+		final String wrongMasterName = "wrongMasterName";
+		new Thread(new Runnable() {
+			@Override
+			public void run() {
+				try {
+					TimeUnit.SECONDS.sleep(3);
+					sentinelJedis1.sentinelMonitor(wrongMasterName,
+							"127.0.0.1", master.getPort(), 2);
+				} catch (InterruptedException e) {
+					e.printStackTrace();
+				}
+
+			}
+		}).start();
+
+		JedisSentinelPool pool = new JedisSentinelPool(wrongMasterName,
+				sentinels);
+		pool.destroy();
+		sentinelJedis1.sentinelRemove(wrongMasterName);
+	}
+
 	@Test
 	public void ensureSafeTwiceFailover() throws InterruptedException {
 		JedisSentinelPool pool = new JedisSentinelPool(MASTER_NAME, sentinels,