Bug 120603 [refactoring] Refactoring History resource mappings should override getModelProviderId()
org.eclipse.ltk.core.refactoring/src/org/eclipse/ltk/core/refactoring/model/RefactoringHistoryResourceMapping.java
public IProject[] getProjects() {
		final IProject[] projects= { null};
		final RefactoringDescriptorProxy[] proxies= fRefactoringHistory.getDescriptors();
		for (int index= 0; index < proxies.length; index++) {
			final String name= proxies[index].getProject();
			if (name != null && !"".equals(name)) 
				projects[0]= ResourcesPlugin.getWorkspace().getRoot().getProject(name);
		}
		return projects;
	}
	/**
	 * {@inheritDoc}
	 */
	public ResourceTraversal[] getTraversals(final ResourceMappingContext context, final IProgressMonitor monitor) throws CoreException {
		if (fResourceTraversals == null) {
			final IProject[] projects= getProjects();
			final ResourceTraversal[] traversals= new ResourceTraversal[projects.length];
			for (int index= 0; index < projects.length; index++)
				traversals[index]= new ResourceTraversal(new IResource[] { projects[index].getFolder(RefactoringHistoryService.NAME_HISTORY_FOLDER)}, IResource.DEPTH_INFINITE, IResource.NONE);
			fResourceTraversals= traversals;
		}
		return fResourceTraversals;
	}
	/**
	 * {@inheritDoc}
	 */
	public int hashCode() {
		return fRefactoringHistory.hashCode();
	}
}