Fixes xetorthio/jedis#758

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

@@ -88,17 +88,18 @@ public class Pipeline extends MultiKeyPipelineBase {
     }
 
     /**
-     * Syncronize pipeline by reading all responses. This operation close the
+     * Synchronize pipeline by reading all responses. This operation close the
      * pipeline. In order to get return values from pipelined commands, capture
      * the different Response<?> of the commands you execute.
      */
     public void sync() {
+        if (client.isConnected()) {
             List<Object> unformatted = client.getMany(getPipelinedResponseLength());
             for (Object o : unformatted) {
                 generateResponse(o);
             }
         }
-
+    }
     /**
      * Syncronize pipeline by reading all responses. This operation close the
      * pipeline. Whenever possible try to avoid using this version and use
@@ -108,6 +109,7 @@ public class Pipeline extends MultiKeyPipelineBase {
      * @return A list of all the responses in the order you executed them.
      */
     public List<Object> syncAndReturnAll() {
+        if (client.isConnected()) {
             List<Object> unformatted = client.getMany(getPipelinedResponseLength());
             List<Object> formatted = new ArrayList<Object>();
 
@@ -119,6 +121,9 @@ public class Pipeline extends MultiKeyPipelineBase {
                 }
             }
             return formatted;
+        } else {
+            return java.util.Collections.<Object>emptyList();
+        }
     }
 
     public Response<String> discard() {