fix for open editor and model change sync up

editor/tools/plugins/com.google.dart.tools.ui/src/com/google/dart/tools/ui/internal/text/editor/WorkingCopyManager.java

 /*
  * Copyright (c) 2011, the Dart project authors.
  * 
  * Licensed under the Eclipse Public License v1.0 (the "License"); you may not use this file except
  * in compliance with the License. You may obtain a copy of the License at
  * 
  * http://www.eclipse.org/legal/epl-v10.html
  * 
  * Unless required by applicable law or agreed to in writing, software distributed under the License
  * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
  * or implied. See the License for the specific language governing permissions and limitations under
  * the License.
  */
 package com.google.dart.tools.ui.internal.text.editor;
 
+import com.google.dart.tools.core.DartCore;
+import com.google.dart.tools.core.internal.model.CompilationUnitImpl;
 import com.google.dart.tools.core.model.CompilationUnit;
 import com.google.dart.tools.ui.IWorkingCopyManager;
 import com.google.dart.tools.ui.IWorkingCopyManagerExtension;
 import com.google.dart.tools.ui.internal.util.DartModelUtil;
 
 import org.eclipse.core.runtime.Assert;
 import org.eclipse.core.runtime.CoreException;
 import org.eclipse.ui.IEditorInput;
+import org.eclipse.ui.part.FileEditorInput;
 
 import java.util.HashMap;
 import java.util.Map;
 
 /**
  * This working copy manager works together with a given compilation unit document provider and
  * additionally offers to "overwrite" the working copy provided by this document provider.
  */
 public class WorkingCopyManager implements IWorkingCopyManager, IWorkingCopyManagerExtension {
 
@@ skipping 37 matching lines @@
    * @param primaryOnly if <code>true</code> only primary working copies will be returned
    * @return the working copy of the compilation unit, or <code>null</code> if the input does not
    *         encode an editor input, or if there is no remembered working copy for this compilation
    *         unit
    */
   public CompilationUnit getWorkingCopy(IEditorInput input, boolean primaryOnly) {
     CompilationUnit unit = fMap == null ? null : fMap.get(input);
     if (unit == null) {
       unit = fDocumentProvider.getWorkingCopy(input);
     }
-    if (unit != null && (!primaryOnly || DartModelUtil.isPrimary(unit))) {
-      return unit;
+    if (unit != null) {
+      if (unit instanceof CompilationUnitImpl && input instanceof FileEditorInput) {
+        return (CompilationUnit) DartCore.create(((FileEditorInput) input).getFile());
+      } else if (!primaryOnly || DartModelUtil.isPrimary(unit)) {
+        return unit;
+      }
     }
+
     return null;
   }
 
   @Override
   public void removeWorkingCopy(IEditorInput input) {
     fMap.remove(input);
     if (fMap.isEmpty()) {
       fMap = null;
     }
   }
@@ skipping 17 matching lines @@
           fMap.clear();
           fMap = null;
         }
         fDocumentProvider.shutdown();
       } finally {
         fIsShuttingDown = false;
       }
     }
   }
 }