mem leak fix

java/debugger/impl/src/com/intellij/debugger/ui/impl/watch/DebuggerTree.java

@@ -324,6 +324,9 @@ public abstract class DebuggerTree extends DebuggerTreeBase implements DataProvi
     }
     else {
       showMessage(session != null? session.getStateDescription() : DebuggerBundle.message("status.debug.stopped"));
+      if (session == null || session.isStopped()) {
+        getNodeFactory().clearHistory(); // save memory by clearing references on JDI objects
+      }
     }
   }
 

java/debugger/impl/src/com/intellij/debugger/ui/impl/watch/NodeManagerImpl.java

@@ -122,10 +122,14 @@ public class NodeManagerImpl extends NodeDescriptorFactoryImpl implements NodeMa
   }
 
   public void dispose() {
-    myHistories.clear();
+    clearHistory();
     super.dispose();
   }
 
+  public void clearHistory() {
+    myHistories.clear();
+  }
+
   private DebuggerTree getTree() {
     return myDebuggerTree;
   }