VTree$TreeNode avoid NPE triggered by external ONLOAD events (#18563)

If an ONLOAD event fires but the target is not the icon, an NPE
occurs. The isCaptionElement method has already used the check
against null before any call happens on the icon which logic is
enough for the onBrowserEvent check as well.

Change-Id: I64de45a07f50f113dcfcb4556f0d8adeea9e1b1b

diff --git a/client/src/com/vaadin/client/ui/VTree.java b/client/src/com/vaadin/client/ui/VTree.java
index 846b16d0cb1f185706317c08ab9752e2cfe2dd74..719b2b91b0dea07acd54373fb6246b4317fc2413 100644 (file)
--- a/client/src/com/vaadin/client/ui/VTree.java
+++ b/client/src/com/vaadin/client/ui/VTree.java
@@ -707,7 +707,7 @@ public class VTree extends FocusElementPanel implements VHasDropHandler,
             final int type = DOM.eventGetType(event);
             final Element target = DOM.eventGetTarget(event);
 
-            if (type == Event.ONLOAD && target == icon.getElement()) {
+            if (type == Event.ONLOAD && icon != null && target == icon.getElement()) {
                 iconLoaded.trigger();
             }