From 78ae8b87003c65eff28c97eef4ab46bdc7aef2f5 Mon Sep 17 00:00:00 2001
From: Henrik Paul <henrik@vaadin.com>
Date: Sat, 7 Dec 2013 01:56:10 +0200
Subject: [PATCH] Fixes a cache range error (#12645)

Change-Id: I1b1a76978ae39ce93aadcf4859d9eb1d55605694
---
 .../vaadin/client/data/AbstractRemoteDataSource.java  | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/client/src/com/vaadin/client/data/AbstractRemoteDataSource.java b/client/src/com/vaadin/client/data/AbstractRemoteDataSource.java
index bda923ef6f..ff8847ea44 100644
--- a/client/src/com/vaadin/client/data/AbstractRemoteDataSource.java
+++ b/client/src/com/vaadin/client/data/AbstractRemoteDataSource.java
@@ -210,7 +210,16 @@ public abstract class AbstractRemoteDataSource<T> implements DataSource<T> {
                 cached = newUsefulData;
             } else {
                 discardStaleCacheEntries();
-                cached = cached.combineWith(newUsefulData);
+
+                /*
+                 * everything might've become stale so we need to re-check for
+                 * emptiness.
+                 */
+                if (!cached.isEmpty()) {
+                    cached = cached.combineWith(newUsefulData);
+                } else {
+                    cached = newUsefulData;
+                }
             }
         }
 
-- 
2.39.5