Don't allow null view providers (#17028)

Change-Id: I5ce4885f19aaac2d4454b5a368f3e58453cf76f9

2 files changed, 24 insertions, 1 deletions

diff --git a/server/src/com/vaadin/navigator/Navigator.java b/server/src/com/vaadin/navigator/Navigator.java
index 65b3fec488..bd2b5711f8 100644
--- a/server/src/com/vaadin/navigator/Navigator.java
+++ b/server/src/com/vaadin/navigator/Navigator.java
@@ -745,9 +745,15 @@ public class Navigator implements Serializable {
      * the requested view name is found.
      * 
      * @param provider
-     *            provider to register
+     *            provider to register, not <code>null</code>
+     * @throws IllegalArgumentException
+     *             if the provided view provider is <code>null</code>
      */
     public void addProvider(ViewProvider provider) {
+        if (provider == null) {
+            throw new IllegalArgumentException(
+                    "Cannot add a null view provider");
+        }
         providers.add(provider);
     }
 
diff --git a/server/tests/src/com/vaadin/tests/server/navigator/NavigatorTest.java b/server/tests/src/com/vaadin/tests/server/navigator/NavigatorTest.java
index ff6028648e..2c045d53fa 100644
--- a/server/tests/src/com/vaadin/tests/server/navigator/NavigatorTest.java
+++ b/server/tests/src/com/vaadin/tests/server/navigator/NavigatorTest.java
@@ -712,4 +712,21 @@ public class NavigatorTest extends TestCase {
         navigator.addView("view", view);
         navigator.navigateTo("view");
     }
+
+    public void testNullViewProvider() {
+        IMocksControl control = EasyMock.createControl();
+        NavigationStateManager manager = control
+                .createMock(NavigationStateManager.class);
+        ViewDisplay display = control.createMock(ViewDisplay.class);
+
+        // create navigator to test
+        Navigator navigator = createNavigator(manager, display);
+
+        try {
+            navigator.addProvider(null);
+            fail("Should not be allowed to add a null view provider");
+        } catch (IllegalArgumentException e) {
+            // Expected
+        }
+    }
 }