Bug 199225 [Automation][Regression] NPE caught when preview attached report in web viewer
steps to reproduce: - use the attached report design - preview in web viewer expected behavior: - report should be rendered properly actual behavior: - NPE caught
engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/layout/html/buffer/HTMLPageBuffer.java
{
	protected INode currentNode;
	protected PageHintGenerator generator;
	
	protected HTMLLayoutContext context;
	
	protected boolean isRepeated = false ;
	
	public HTMLPageBuffer(HTMLLayoutContext context)
	{
		this.context = context;
		this.generator = new PageHintGenerator();
	}
	
	public void startContainer(IContent content, boolean isFirst, IContentEmitter emitter)
	{
		int type = content.getContentType( );
		switch(type)
		{
			case IContent.TABLE_BAND_CONTENT:
			case IContent.LIST_BAND_CONTENT:
				boolean first = isFirst && !isRepeated;
				BlockStackingNode bandNode = new BlockStackingNode(content, emitter, generator);
				setup(bandNode, first);
				currentNode = bandNode;
				break;
			case IContent.ROW_CONTENT:
				InlineStackingNode inlineNode = new InlineStackingNode(content, emitter, generator);
				setup(inlineNode, isFirst);
				currentNode = inlineNode;