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
/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.birt.report.model.api.metadata.IElementDefn#isPropertyVisible(java.lang.String)
	 */
	public boolean isPropertyVisible( String propName )
	{
		IPropertyDefn propDefn = getProperty( propName );
		if ( propDefn == null )
			return false;
		if ( propDefn.getTypeCode( ) == IPropertyType.STRUCT_TYPE )
			return false;
		String visibility = getPropertyVisibility( propDefn.getName( ) );
		if ( HIDDEN_IN_PROPERTY_SHEET.equals( visibility ) )
			return false;
		return true;
	}
	/**
	 * Returns the visibility of a given property.
	 * 
	 * @param propName
	 *            the property name
	 * @return the visibility of the property
	 */
	private String getPropertyVisibility( String propName )
	{
		ElementDefn elementDefn = this;
		while ( elementDefn != null )
		{
			if ( elementDefn.propVisibilites != null )