From 6c73f2643f2d418d07f2c33d9d2a681ba8fee1df Mon Sep 17 00:00:00 2001
From: =?utf8?q?Leif=20=C3=85strand?= <leif@vaadin.com>
Date: Thu, 21 Jun 2012 14:51:59 +0300
Subject: [PATCH] Show sensible message if variable change target isn't a
 VariableOwner

---
 .../gwt/server/AbstractCommunicationManager.java   | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/src/com/vaadin/terminal/gwt/server/AbstractCommunicationManager.java b/src/com/vaadin/terminal/gwt/server/AbstractCommunicationManager.java
index e04857f800..ecd4fdd1ad 100644
--- a/src/com/vaadin/terminal/gwt/server/AbstractCommunicationManager.java
+++ b/src/com/vaadin/terminal/gwt/server/AbstractCommunicationManager.java
@@ -1535,8 +1535,18 @@ public abstract class AbstractCommunicationManager implements Serializable {
                     Map<String, Object> changes = legacyInvocation
                             .getVariableChanges();
                     try {
-                        changeVariables(source, (VariableOwner) connector,
-                                changes);
+                        if (connector instanceof VariableOwner) {
+                            changeVariables(source, (VariableOwner) connector,
+                                    changes);
+                        } else {
+                            throw new IllegalStateException(
+                                    "Received legacy variable change for "
+                                            + connector.getClass().getName()
+                                            + " ("
+                                            + connector.getConnectorId()
+                                            + ") which is not a VariableOwner. The client-side connector sent these legacy varaibles: "
+                                            + changes.keySet());
+                        }
                     } catch (Exception e) {
                         Component errorComponent = null;
                         if (connector instanceof Component) {
-- 
2.39.5