Allow removing Window while iterating child window set (#9251)

svn changeset:24115/svn branch:6.8

2 files changed, 19 insertions, 1 deletions

diff --git a/src/com/vaadin/ui/Window.java b/src/com/vaadin/ui/Window.java
index 32415433ad..fce9a30c82 100644
--- a/src/com/vaadin/ui/Window.java
+++ b/src/com/vaadin/ui/Window.java
@@ -10,6 +10,7 @@ import java.net.MalformedURLException;
 import java.net.URL;
 import java.util.ArrayList;
 import java.util.Collections;
+import java.util.HashSet;
 import java.util.Iterator;
 import java.util.LinkedHashSet;
 import java.util.LinkedList;
@@ -1549,7 +1550,7 @@ public class Window extends Panel implements URIHandler, ParameterHandler,
      * @return Set of child windows.
      */
     public Set<Window> getChildWindows() {
-        return Collections.unmodifiableSet(subwindows);
+        return Collections.unmodifiableSet(new HashSet<Window>(subwindows));
     }
 
     /**
diff --git a/tests/server-side/com/vaadin/tests/server/component/window/AddRemoveSubWindow.java b/tests/server-side/com/vaadin/tests/server/component/window/AddRemoveSubWindow.java
index 50de91e2af..74859fd8b7 100644
--- a/tests/server-side/com/vaadin/tests/server/component/window/AddRemoveSubWindow.java
+++ b/tests/server-side/com/vaadin/tests/server/component/window/AddRemoveSubWindow.java
@@ -5,6 +5,8 @@ import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertTrue;
 
+import java.util.Set;
+
 import org.junit.Test;
 
 import com.vaadin.Application;
@@ -80,4 +82,19 @@ public class AddRemoveSubWindow {
         assertTrue("Window was not removed correctly", removed);
         assertNull(subWindow.getParent());
     }
+
+    @Test
+    public void testChildWindowsIteratorModification() {
+        Window mainWindow = new Window();
+        mainWindow.addWindow(new Window());
+        mainWindow.addWindow(new Window());
+
+        Set<Window> childWindows = mainWindow.getChildWindows();
+        for (Window window : childWindows) {
+            mainWindow.removeWindow(window);
+        }
+
+        assertEquals(2, childWindows.size());
+        assertEquals(0, mainWindow.getChildWindows().size());
+    }
 }