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
return getPropertyListWithType( getProperties( ),
				IPropertyType.EXPRESSION_TYPE );
	}
	/**
	 * Returns the expression property definition list of this element
	 * definition. Each one is the instance of <code>PropertyDefn</code>.
	 * 
	 * @return the expression property definition list.
	 */
	public List getLocalExpressions( )
	{
		return getPropertyListWithType( getLocalProperties( ),
				IPropertyType.EXPRESSION_TYPE );
	}
	/**
	 * Returns the property definition list each of which is defined in given
	 * property definition list with the given type.
	 * 
	 * @param propList
	 *            the property definition to search
	 * @param type
	 *            property type code, It's the constant defined in
	 *            <code>PropertyType</code>.
	 * @return the property definition list
	 */
	private List getPropertyListWithType( List propList, int type )
	{
		List props = new ArrayList( );
		Iterator iter = propList.iterator( );
		while ( iter.hasNext( ) )