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
/**
	 * Returns the external script defined in the extended element model.
	 * 
	 * @return the script
	 */
	public String getExternalScript( )
	{
		String propName = ( (ExtendedItem) getElement( ) )
				.getScriptPropertyName( );
		if ( propName == null )
			return null;
		return getStringProperty( propName );
	}
	/**
	 * Sets the scripts in the extension element model.
	 * 
	 * @param theScript
	 *            the script to be set
	 * @throws SemanticException
	 *             if fail to set the scripts
	 */
	public void setExternalScript( String theScript ) throws SemanticException
	{
		String propName = ( (ExtendedItem) getElement( ) )
				.getScriptPropertyName( );
		if ( propName == null )
			return;
		setStringProperty( propName, theScript );
	}
}