fix failing tests (hopefully)

core/src/main/java/hudson/model/Queue.java

@@ -747,7 +747,13 @@ public class Queue extends ResourceController implements Saveable {
 
     public boolean cancel(Item item) {
         LOGGER.log(Level.FINE, "Cancelling {0} item#{1}", new Object[] {item.task, item.id});
-        return item.cancel(this);
+        lock.lock();
+        try {
+            return item.cancel(this);
+        } finally {
+            updateSnapshot();
+            lock.unlock();
+        }
     }
 
     /**

test/src/test/java/jenkins/model/JenkinsReloadConfigurationTest.java

@@ -47,7 +47,7 @@ public class JenkinsReloadConfigurationTest {
     }
 
     private void modifyNode(Node node) throws Exception {
-        replace("config.xml", "oldLabel", "newLabel");
+        replace(String.format("nodes/%s/config.xml",node.getNodeName()), "oldLabel", "newLabel");
 
         assertEquals("oldLabel", node.getLabelString());