fixes #5340

svn changeset:14175/svn branch:6.4

diff --git a/src/com/vaadin/ui/AbstractComponentContainer.java b/src/com/vaadin/ui/AbstractComponentContainer.java
index 8df78be32887c812393d650f642d26a0bff53dff..73093c41238b03638dc7fecceaabab2391a3b249 100644 (file)
--- a/src/com/vaadin/ui/AbstractComponentContainer.java
+++ b/src/com/vaadin/ui/AbstractComponentContainer.java
@@ -259,7 +259,7 @@ public abstract class AbstractComponentContainer extends AbstractComponent
         if (childrenMayBecomeUndefined) {
             Collection<Component> previouslyInvalidComponents = invalidChildren;
             invalidChildren = getInvalidSizedChildren(vertical);
-            if (previouslyInvalidComponents != null) {
+            if (previouslyInvalidComponents != null && invalidChildren != null) {
                 for (Iterator<Component> iterator = invalidChildren.iterator(); iterator
                         .hasNext();) {
                     Component component = iterator.next();