Bug 153405 Null parameter value is inconsistent between designer and preview
Description: Null parameter value is inconsistent between designer and preview Steps to reproduce: 1. New a report parameter, list-box, tick AllowNull. 2. Click New button, click OK without input anything. 3. Drag the parameter to Layout and preview Actual result: After step2, display text is "Null" and value is empty. However, when preview, the display text is "Null Value". Expected result: Display text and value should be consistent between Edit Parameter Dialog in Layout and Parameter dialog during preview.
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/ui/dialogs/ParameterDialog.java
private boolean matchDataType( ResultSetColumnHandle column )
	{
		String type = getSelectedDataType( );
		if ( type.equals( DesignChoiceConstants.PARAM_TYPE_STRING )
				|| DesignChoiceConstants.COLUMN_DATA_TYPE_ANY.equals( column.getDataType( ) ) )
		{
			return true;
		}
		if ( DesignChoiceConstants.COLUMN_DATA_TYPE_DATETIME.equals( column.getDataType( ) ) )
		{
			return type.equals( DesignChoiceConstants.PARAM_TYPE_DATETIME );
		}
		else if ( DesignChoiceConstants.COLUMN_DATA_TYPE_DECIMAL.equals( column.getDataType( ) ) )
		{
			return type.equals( DesignChoiceConstants.PARAM_TYPE_DECIMAL );
		}
		else if ( DesignChoiceConstants.COLUMN_DATA_TYPE_FLOAT.equals( column.getDataType( ) ) )
		{
			return type.equals( DesignChoiceConstants.PARAM_TYPE_FLOAT );
		}
		else if ( DesignChoiceConstants.COLUMN_DATA_TYPE_INTEGER.equals( column.getDataType( ) ) )
		{
			return type.equals( DesignChoiceConstants.PARAM_TYPE_INTEGER );
		}
		return false;
	}
	private String getInputControlType( )
	{
		String type = null;
		if ( inputParameter.getControlType( ) == null )