Bug 151202 [regression]Set default master page to item in cell will cause blank page
Description: Set default master page to item in cell will cause blank page Steps to reproduce: 1. New a report 2. Insert a grid(1*1) 3. Insert a label to grid cell 4. Select the label and set default master page to it 5. Preview in Web Viewer and pdf Expected result: No blank page, just one page for grid display. Actual result: A blank page before grid page
engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/layout/html/HTMLAbstractLM.java
}
		return false;
	}
	/**
	 * execute the executor, drip all its children contents.
	 * 
	 * @param executor
	 */
	private void traverse( IReportItemExecutor executor )
	{
		assert executor != null;
		while ( executor.hasNextChild( ) )
		{
			IReportItemExecutor child = (IReportItemExecutor) executor
					.getNextChild( );
			if ( child != null )
			{
				child.execute( );
				traverse( child );
				child.close( );
			}
		}
	}
	/**
	 * execute the report and add all its contents into the content.
	 * 
	 * @param content
	 * @param executor
	 */
	protected void execute( IContent content, IReportItemExecutor executor )