Bug 148747 Design become invalid when I extend a masterpage from Library
The attachment contains a report file and a library file. Reproduce: 1. Deploy the library("lib"), and open the report. 2. Drag Masterpage("page1") from "lib" to report. 3. Reopen the report, it become invalid.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/api/ExtendedItemHandle.java
if ( ( (ExtendedItem) getElement( ) ).getExtDefn( ) != null )
			return ( (ExtendedItem) getElement( ) ).getExtDefn( )
					.getLocalProperties( );
		return Collections.EMPTY_LIST;
	}
	/**
	 * Returns the methods defined on the extension element definition and the
	 * methods defined within the extension model property inside.
	 * 
	 * @return the list of methods
	 */
	public List getMethods( )
	{
		return ( (ExtendedItem) getElement( ) ).getMethods( );
	}
	/**
	 * Returns an iterator over filter. The iterator returns instances of
	 * <code>FilterConditionHandle</code> that represents filter condition
	 * object.
	 * 
	 * @return iterator over filters.
	 * 
	 * @see org.eclipse.birt.report.model.api.elements.structures.FilterCondition
	 */
	public Iterator filtersIterator( )
	{
		PropertyHandle propHandle = getPropertyHandle( ExtendedItem.FILTER_PROP );
		assert propHandle != null;
		return propHandle.iterator( );
	}