Bug 385043

Description Tiziano Leidi 2012-07-13 08:13:43 EDT

Hi People,
we installed the new Eclipse 4.2 and we are currently facing the following problem in GMF code.

In the class [code]ClipboardSupportUtil[/code] (GMF) there is the following method.

[code]	public static EObject appendEObjectAt(EObject eObject,
			EReference reference, EObject referencedObject) {
		if (isOkToAppendEObjectAt(eObject, reference, referencedObject) == false) {
			return null;
		}
		if (reference.isContainment()) {
            ((InternalEObject)referencedObject).eSetResource(null,null);
			sendCreateEvent(referencedObject);
		}
		((Collection) eObject.eGet(reference)).add(referencedObject);
		return referencedObject;
	}[/code]

which calls [code]eSetResource(null,null)[/code]

The implementation of [code]eSetResource [/code]has changed in EMF from the previous version, ... in BasicEObjectImpl now there is the following new implementation

[code]  public NotificationChain eSetResource(Resource.Internal resource, NotificationChain notifications)
  {
    Resource.Internal oldResource = eDirectResource();
    // When setting the resource to null we assume that detach has already been called in the resource implementation
    //
    if (oldResource != null && resource != null)
    {
      notifications = ((InternalEList<?>)oldResource.getContents()).basicRemove(this, notifications);
      oldResource.detached(this);
    }[/code]

which previously was(Eclipse Indigo)

[code]  public NotificationChain eSetResource(Resource.Internal resource, NotificationChain notifications)
  {
    Resource.Internal oldResource = eDirectResource();
    if (oldResource != null)
    {
      notifications = ((InternalEList<?>)oldResource.getContents()).basicRemove(this, notifications);

      // When setting the resource to null we assume that detach has already been called in the resource implementation
      //
      if (resource != null)
      {
        oldResource.detached(this);
      }
    }[/code]

As a consequence, the behavior is different for a call [code]eSetResource(null,null)[/code] and the object is not removed from the resource with [code]basicRemove[/code] as it previously was.

I had the following answer from Ed Merks:

This change was made to fix <a
href="https://bugs.eclipse.org/bugs/show_bug.cgi?id=346805">https://bugs.eclipse.org/bugs/show_bug.cgi?id=346805</a>.

This API was never intended to be called directly by clients:
/**
* Sets this object to be directly contained by the resource
* and returns accumulated notifications.
* This is only done as the inverse of {@link
Resource#getContents()}&lt;code&gt;.add(this)&lt;/code&gt;.
* @return accumulated notifications.
*/
NotificationChain eSetResource(Resource.Internal
resource, NotificationChain notifications);

The GMF code should be using resource.getContents().remove(...).
  
I.e., perhaps it should be
referencedObject.eResource().getContents().remove(referencedObject)
though I'm not sure if the referenced object is necessarily
contained directly in a resource so maybe it should check that
eResource() isn't null.

You should open a bugzilla for the GMF runtime to fix this.

...

Many thanks
Tiziano