Support null sortParams in Lettuce and SRP sort

DATAREDIS-217

src/test/java/org/springframework/data/redis/connection/AbstractConnectionIntegrationTests.java

@@ -712,6 +712,17 @@ public abstract class AbstractConnectionIntegrationTests {
 						Arrays.asList(new String[] { "bar", "baz", "foo" }) }), actual);
 	}
 
+	@Test
+	public void testSortNullParams() {
+		actual.add(connection.rPush("sortlist", "5"));
+		actual.add(connection.rPush("sortlist", "2"));
+		actual.add(connection.rPush("sortlist", "3"));
+		actual.add(connection.sort("sortlist", null));
+		verifyResults(
+				Arrays.asList(new Object[] { 1l, 2l, 3l,
+						Arrays.asList(new String[] { "2", "3", "5" }) }), actual);
+	}
+
 	@Test
 	public void testDbSize() {
 		connection.set("dbparam", "foo");

src/test/java/org/springframework/data/redis/connection/jedis/JedisConnectionPipelineIntegrationTests.java

@@ -83,6 +83,10 @@ public class JedisConnectionPipelineIntegrationTests extends
 	public void testSortStore() {
 	}
 
+	@Ignore("DATAREDIS-143 Pipeline tries to return Long instead of List<String> on sort with no params")
+	public void testSortNullParams() {
+	}
+
 	@Ignore("DATAREDIS-143 Jedis ClassCastExceptions closing pipeline on certain ops")
 	public void testMultiExec() {
 	}

src/test/java/org/springframework/data/redis/connection/jredis/JRedisConnectionIntegrationTests.java

@@ -543,6 +543,16 @@ public class JRedisConnectionIntegrationTests extends AbstractConnectionIntegrat
 		assertEquals(Arrays.asList(new String[] { "bar", "baz", "foo" }), connection.lRange("newlist", 0, 9));
 	}
 
+	@Test
+	public void testSortNullParams() {
+		connection.rPush("sortlist", "5");
+		connection.rPush("sortlist", "2");
+		connection.rPush("sortlist", "3");
+		actual.add(connection.sort("sortlist", null));
+		verifyResults(
+			Arrays.asList(new Object[] { Arrays.asList(new String[] { "2", "3", "5" }) }), actual);
+	}
+
 	@Test
 	public void testLPop() {
 		connection.rPush("PopList", "hello");