2 files changed, 45 insertions, 0 deletions
diff --git a/uitest/src/main/java/com/vaadin/tests/layoutmanager/ConcurrentModificationUI.java b/uitest/src/main/java/com/vaadin/tests/layoutmanager/ConcurrentModificationUI.java
new file mode 100644
index 0000000000..2a3370e381
--- /dev/null
+++ b/uitest/src/main/java/com/vaadin/tests/layoutmanager/ConcurrentModificationUI.java
@@ -0,0 +1,29 @@
+package com.vaadin.tests.layoutmanager;
+
+import com.vaadin.server.VaadinRequest;
+import com.vaadin.ui.Alignment;
+import com.vaadin.ui.CssLayout;
+import com.vaadin.ui.FormLayout;
+import com.vaadin.ui.HorizontalLayout;
+import com.vaadin.ui.Panel;
+import com.vaadin.ui.UI;
+
+public class ConcurrentModificationUI extends UI {
+
+    @Override
+    protected void init(VaadinRequest request) {
+        Panel panel = new Panel();
+        setContent(panel);
+
+        FormLayout form = new FormLayout();
+        panel.setContent(form);
+
+        HorizontalLayout horizLyt = new HorizontalLayout();
+        form.addComponent(horizLyt);
+
+        CssLayout cssLyt = new CssLayout();
+        horizLyt.addComponent(cssLyt);
+        horizLyt.setComponentAlignment(cssLyt, Alignment.MIDDLE_LEFT);
+    }
+
+}
diff --git a/uitest/src/test/java/com/vaadin/tests/layoutmanager/ConcurrentModificationUITest.java b/uitest/src/test/java/com/vaadin/tests/layoutmanager/ConcurrentModificationUITest.java
new file mode 100644
index 0000000000..4a64fc3173
--- /dev/null
+++ b/uitest/src/test/java/com/vaadin/tests/layoutmanager/ConcurrentModificationUITest.java
@@ -0,0 +1,16 @@
+package com.vaadin.tests.layoutmanager;
+
+import org.junit.Test;
+
+import com.vaadin.tests.tb3.SingleBrowserTest;
+
+public class ConcurrentModificationUITest extends SingleBrowserTest {
+
+    @Test
+    public void noExceptionWhenEnlarging() {
+        testBench().resizeViewPortTo(100, 100);
+        openTestURL("debug");
+        testBench().resizeViewPortTo(200, 200);
+        assertNoErrorNotifications();
+    }
+}