Bug 136027 [Smoke]the report with a gounp can not preview
Description: the report with a gounp can not preview Steps to reproduce: 1. new a datasource and a dataset 2. drag the dataset to the layout 3. Add a group on the table. save and preview. Actual result: "Error happened while running the report" is appeared.
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/ui/dialogs/GroupDialog.java
public void setInput( Object input )
	{
		Assert.isTrue( input instanceof GroupHandle );
		inputGroup = (GroupHandle) input;
	}
	/**
	 * Sets the dataset list to use.
	 * 
	 * @param dataSetList
	 */
	
	
	
	
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.jface.dialogs.Dialog#okPressed()
	 */
	protected void okPressed( )
	{
		try
		{
			inputGroup.setName( nameEditor.getText( ) );
			String newToc = UIUtil.convertToModelString( tocEditor.getText( ),
					true );
			if ( newToc != inputGroup.getTocExpression( ) )
			{
				if ( newToc == null
						|| !newToc.equals( inputGroup.getTocExpression( ) ) )