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/pdf/PDFAbstractLM.java
protected boolean isPageBreakAfter( )
	{
		if ( canPageBreak( ) )
		{
			return needPageBreakAfter( );
		}
		return false;
	}
	protected boolean canPageBreak( )
	{
		if ( !context.allowPageBreak( ) )
		{
			return false;
		}
		PDFAbstractLM p = parent;
		while ( p != null )
		{
			if ( !p.allowPageBreak( ) )
			{
				return false;
			}
			p = p.getParent( );
		}
		return true;
	}
	protected boolean needPageBreakBefore( )
	{
		if ( content == null )
		{
			return false;