[isis] branch master updated: ISIS-2361: fix potential NPE with workaround

[ahuber]

This is an automated email from the ASF dual-hosted git repository.

ahuber pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/isis.git


The following commit(s) were added to refs/heads/master by this push:
     new 45453aa  ISIS-2361: fix potential NPE with workaround
45453aa is described below

commit 45453aa0d8ed864eb4c533b8514dfcab584673d1
Author: Andi Huber <ahu...@apache.org>
AuthorDate: Tue May 12 09:02:34 2020 +0200

    ISIS-2361: fix potential NPE with workaround
---
 .../ui/components/widgets/select2/Select2MultiChoiceExt.java      | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git 
a/viewers/wicket/ui/src/main/java/org/apache/isis/viewer/wicket/ui/components/widgets/select2/Select2MultiChoiceExt.java
 
b/viewers/wicket/ui/src/main/java/org/apache/isis/viewer/wicket/ui/components/widgets/select2/Select2MultiChoiceExt.java
index acbb693..668b65a 100644
--- 
a/viewers/wicket/ui/src/main/java/org/apache/isis/viewer/wicket/ui/components/widgets/select2/Select2MultiChoiceExt.java
+++ 
b/viewers/wicket/ui/src/main/java/org/apache/isis/viewer/wicket/ui/components/widgets/select2/Select2MultiChoiceExt.java
@@ -20,6 +20,7 @@ package 
org.apache.isis.viewer.wicket.ui.components.widgets.select2;
 
 import java.util.ArrayList;
 import java.util.Collection;
+import java.util.Collections;
 
 import org.apache.wicket.model.IModel;
 import org.wicketstuff.select2.Select2MultiChoice;
@@ -30,6 +31,8 @@ import 
org.apache.isis.core.webapp.context.memento.ObjectMemento;
 import org.apache.isis.viewer.wicket.model.models.ScalarModel;
 import 
org.apache.isis.viewer.wicket.ui.components.widgets.select2.providers.EmptyChoiceProvider;
 
+import lombok.val;
+
 public class Select2MultiChoiceExt
 extends Select2MultiChoice<ObjectMemento>
 implements ChoiceExt {
@@ -72,7 +75,10 @@ implements ChoiceExt {
     
     @Override
     public Collection<ObjectMemento> getModelObject() {
-        return new ArrayList<>(super.getModelObject());
+        val modelObj = super.getModelObject();
+        return modelObj==null
+                ? Collections.emptyList() 
+                : new ArrayList<>(modelObj);
     }
     
 }