Bug 168808 Display text is lost after launching import values dialog
Steps to reproduce: 1.new a parameter; 2.select list box control type; 3.press "Import Values" button to import some values; 4.assign display texts for the imported values; 5.press "Import Values" button to launch import values dialog again; 6.press ok button on dialog; Expected result: The previous assigned display texts are remained. Actual result: The previous display texts are lost.
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/ui/dialogs/ParameterDialog.java
{
			ResultSetColumnHandle cachedColumn = (ResultSetColumnHandle) iter.next( );
			if ( DEUtil.getExpression( cachedColumn ).equals( expression ) )
			{
				return cachedColumn.getColumnName( );
			}
		}
		
		return expression;
	}
	private String getInputControlDisplayName( )
	{
		String type = getInputControlType( );
		String displayName = null;
		if ( CONTROL_TYPE_CHOICE_SET.findChoice( type ) != null )
		{
			displayName = CONTROL_TYPE_CHOICE_SET.findChoice( type )
					.getDisplayName( );
		}
		else
		{
			if ( PARAM_CONTROL_COMBO.equals( type ) )
			{
				displayName = DISPLAY_NAME_CONTROL_COMBO;
			}
			else if ( PARAM_CONTROL_LIST.equals( type ) )
			{
				displayName = DISPLAY_NAME_CONTROL_LIST;
			}
		}