TreeUiTests fixed

platform/core-impl/src/com/intellij/mock/MockApplication.java

@@ -210,24 +210,24 @@ public class MockApplication extends MockComponentManager implements Application
   @NotNull
   @Override
   public ModalityState getCurrentModalityState() {
-    throw new UnsupportedOperationException();
+    return getNoneModalityState();
   }
 
   @Override
   public ModalityState getAnyModalityState() {
-    throw new UnsupportedOperationException();
+    return getNoneModalityState();
   }
 
   @NotNull
   @Override
   public ModalityState getModalityStateForComponent(@NotNull Component c) {
-    throw new UnsupportedOperationException();
+    return getNoneModalityState();
   }
 
   @NotNull
   @Override
   public ModalityState getDefaultModalityState() {
-    throw new UnsupportedOperationException();
+    return getNoneModalityState();
   }
 
   @Override

platform/platform-api/src/com/intellij/ide/util/treeView/AbstractTreeUi.java

@@ -1330,6 +1330,10 @@ public class AbstractTreeUi {
                   }
                 }
 
+                if (!canInitiateNewActivity()) {
+                  throw new ProcessCanceledException();
+                }
+
                 final Object element = getElementFor(node);
                 addNodeAction(element, new NodeAction() {
                   public void onReady(final DefaultMutableTreeNode node) {