2 files changed, 22 insertions, 20 deletions
diff --git a/client/src/com/vaadin/client/data/AbstractRemoteDataSource.java b/client/src/com/vaadin/client/data/AbstractRemoteDataSource.java
index 1de271c646..1ab9764337 100644
--- a/client/src/com/vaadin/client/data/AbstractRemoteDataSource.java
+++ b/client/src/com/vaadin/client/data/AbstractRemoteDataSource.java
@@ -166,7 +166,7 @@ public abstract class AbstractRemoteDataSource<T> implements DataSource<T> {
         @Override
         public void updateRow() {
             int index = indexOf(row);
-            if (index >= 0) {
+            if (index >= 0 && dataChangeHandler != null) {
                 dataChangeHandler.dataUpdated(index, 1);
             }
         }
@@ -301,7 +301,7 @@ public abstract class AbstractRemoteDataSource<T> implements DataSource<T> {
                         .partitionWith(cached);
                 handleMissingRows(missingCachePartition[0]);
                 handleMissingRows(missingCachePartition[2]);
-            } else {
+            } else if (dataChangeHandler != null) {
                 dataChangeHandler.dataAvailable(cached.getStart(),
                         cached.length());
             }
@@ -400,7 +400,6 @@ public abstract class AbstractRemoteDataSource<T> implements DataSource<T> {
      *            a list of rows, starting from <code>firstRowIndex</code>
      */
     protected void setRowData(int firstRowIndex, List<T> rowData) {
-
         assert firstRowIndex + rowData.size() <= size();
 
         Profiler.enter("AbstractRemoteDataSource.setRowData");
@@ -450,7 +449,10 @@ public abstract class AbstractRemoteDataSource<T> implements DataSource<T> {
                     cached = newUsefulData;
                 }
             }
-            dataChangeHandler.dataAvailable(cached.getStart(), cached.length());
+            if (dataChangeHandler != null) {
+                dataChangeHandler.dataAvailable(cached.getStart(),
+                        cached.length());
+            }
 
             updatePinnedRows(rowData);
         }
@@ -517,8 +519,9 @@ public abstract class AbstractRemoteDataSource<T> implements DataSource<T> {
             cached = cached.offsetBy(-removedRange.length());
         }
 
-        assertDataChangeHandlerIsInjected();
-        dataChangeHandler.dataRemoved(firstRowIndex, count);
+        if (dataChangeHandler != null) {
+            dataChangeHandler.dataRemoved(firstRowIndex, count);
+        }
         ensureCoverageCheck();
 
         Profiler.leave("AbstractRemoteDataSource.removeRowData");
@@ -563,8 +566,9 @@ public abstract class AbstractRemoteDataSource<T> implements DataSource<T> {
                 keyToIndexMap.remove(getRowKey(row));
             }
         }
-        assertDataChangeHandlerIsInjected();
-        dataChangeHandler.dataAdded(firstRowIndex, count);
+        if (dataChangeHandler != null) {
+            dataChangeHandler.dataAdded(firstRowIndex, count);
+        }
         ensureCoverageCheck();
 
         Profiler.leave("AbstractRemoteDataSource.insertRowData");
@@ -709,15 +713,8 @@ public abstract class AbstractRemoteDataSource<T> implements DataSource<T> {
         size = newSize;
         dropFromCache(getCachedRange());
         cached = Range.withLength(0, 0);
-        assertDataChangeHandlerIsInjected();
-        dataChangeHandler.resetDataAndSize(newSize);
-    }
-
-    private void assertDataChangeHandlerIsInjected() {
-        assert dataChangeHandler != null : "The dataChangeHandler was "
-                + "called before it was injected. Maybe you tried "
-                + "to manipulate the data in the DataSource's "
-                + "constructor instead of in overriding onAttach() "
-                + "and doing it there?";
+        if (dataChangeHandler != null) {
+            dataChangeHandler.resetDataAndSize(newSize);
+        }
     }
 }
diff --git a/client/src/com/vaadin/client/widget/grid/datasources/ListDataSource.java b/client/src/com/vaadin/client/widget/grid/datasources/ListDataSource.java
index 47e072490e..46e972b3e8 100644
--- a/client/src/com/vaadin/client/widget/grid/datasources/ListDataSource.java
+++ b/client/src/com/vaadin/client/widget/grid/datasources/ListDataSource.java
@@ -110,7 +110,9 @@ public class ListDataSource<T> implements DataSource<T> {
 
         @Override
         public void updateRow() {
-            changeHandler.dataUpdated(ds.indexOf(getRow()), 1);
+            if (changeHandler != null) {
+                changeHandler.dataUpdated(ds.indexOf(getRow()), 1);
+            }
         }
     }
 
@@ -389,7 +391,10 @@ public class ListDataSource<T> implements DataSource<T> {
             throw new IllegalStateException(
                     "Trying to fetch rows outside of array");
         }
-        changeHandler.dataAvailable(firstRowIndex, numberOfRows);
+
+        if (changeHandler != null) {
+            changeHandler.dataAvailable(firstRowIndex, numberOfRows);
+        }
     }
 
     @Override