Ensure addItem(null) returns null

Change-Id: I67823b306e68637b469ed35fad00f6af64e8cc15

3 files changed, 8 insertions, 9 deletions

diff --git a/server/src/main/java/com/vaadin/data/util/ContainerHierarchicalWrapper.java b/server/src/main/java/com/vaadin/data/util/ContainerHierarchicalWrapper.java
index 199d186fab..8590528f43 100644
--- a/server/src/main/java/com/vaadin/data/util/ContainerHierarchicalWrapper.java
+++ b/server/src/main/java/com/vaadin/data/util/ContainerHierarchicalWrapper.java
@@ -538,10 +538,9 @@ public class ContainerHierarchicalWrapper implements Container.Hierarchical,
      */
     @Override
     public Item addItem(Object itemId) throws UnsupportedOperationException {
-
         // Null ids are not accepted
         if (itemId == null) {
-            throw new NullPointerException("Container item id can not be null");
+            return null;
         }
 
         final Item item = container.addItem(itemId);
diff --git a/server/src/main/java/com/vaadin/data/util/IndexedContainer.java b/server/src/main/java/com/vaadin/data/util/IndexedContainer.java
index 8783c061ac..c281fb35c1 100644
--- a/server/src/main/java/com/vaadin/data/util/IndexedContainer.java
+++ b/server/src/main/java/com/vaadin/data/util/IndexedContainer.java
@@ -269,7 +269,9 @@ public class IndexedContainer extends
     public Item addItem(Object itemId) {
         Item item = internalAddItemAtEnd(itemId, new IndexedContainerItem(
                 itemId), false);
-        if (!isFiltered()) {
+        if (item == null) {
+            return null;
+        } else if (!isFiltered()) {
             // always the last item
             fireItemAdded(size() - 1, itemId, item);
         } else if (passesFilters(itemId) && !containsId(itemId)) {
@@ -726,11 +728,6 @@ public class IndexedContainer extends
          *            the Item ID of the new Item.
          */
         private IndexedContainerItem(Object itemId) {
-
-            // Gets the item contents from the host
-            if (itemId == null) {
-                throw new NullPointerException();
-            }
             this.itemId = itemId;
         }
 
diff --git a/server/src/test/java/com/vaadin/data/util/AbstractContainerTestBase.java b/server/src/test/java/com/vaadin/data/util/AbstractContainerTestBase.java
index 64f1a31399..138beb7f3d 100644
--- a/server/src/test/java/com/vaadin/data/util/AbstractContainerTestBase.java
+++ b/server/src/test/java/com/vaadin/data/util/AbstractContainerTestBase.java
@@ -219,6 +219,9 @@ public abstract class AbstractContainerTestBase {
             // Add again
             Item item2 = container.addItem("foo");
             Assert.assertNull(item2);
+
+            // Null is not a valid itemId
+            Assert.assertNull(container.addItem(null));
         } catch (UnsupportedOperationException e) {
             // Ignore contains which do not support addItem*
         }
@@ -534,7 +537,7 @@ public abstract class AbstractContainerTestBase {
     /**
      * Override in subclasses to return false if the container getItem() method
      * returns a non-null value for an item that has been filtered out.
-     * 
+     *
      * @return
      */
     protected boolean isFilteredOutItemNull() {