Bug 163018 An error extension will lead the report contain chart can't be opened and can not new a report.
Details: An error extension will lead the report contain chart can't open In org.eclipse.birt.report.tests.model has an error extension. When run the birt use workbenck, the report contain chart can't be opened and it can not new a report.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/metadata/ElementDefn.java
*/
	public IPropertyDefn findProperty( String propName )
	{
		return getProperty( propName );
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.birt.report.model.metadata.ObjectDefn#addProperty(org.eclipse.birt.report.model.metadata.PropertyDefn)
	 */
	public void addProperty( PropertyDefn property ) throws MetaDataException
	{
		MetaDataDictionary dd = MetaDataDictionary.getInstance( );
		
		if ( dd.getElement( extendsFrom ) != null )
		{
			ElementDefn parentTemp = (ElementDefn) dd.getElement( extendsFrom );
			while ( parentTemp != null )
			{
				if ( parentTemp.properties.containsKey( property.getName( ) ) )
				{
					throw new MetaDataException(
							new String[]{property.getName( ), this.name},
							MetaDataException.DESIGN_EXCEPTION_DUPLICATE_PROPERTY );
				}
				parentTemp = (ElementDefn) dd.getElement( parentTemp
						.getExtends( ) );
			}
		}