Bug 153523 OK button in parameter dialog is enabled without default value in combo-box
Description: OK button in parameter dialog is enabled without default value in combo-box Steps to reproduce: 1. New a report parameter, combo-box. 2. Click New button, input abc as value, click OK 3. Set abc as default value and close Edit Parameter dialog. 4. New a data source and dataset 5. Edit the parameter, remove abc value and import values from dataset Expected result: OK button is disabled for there is no default value. Actual result: OK button is enabled.
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/ui/dialogs/ParameterDialog.java
{
				makeUniqueAndValid( );
				refreshValueTable( );
			}
			updateMessageLine( );
		}
	}
	private void clearArea( Composite area )
	{
		Control[] children = area.getChildren( );
		for ( int i = 0; i < children.length; i++ )
		{
			children[i].dispose( );
		}
	}
	private void updateTableButtons( )
	{
		boolean isEnable = true;
		SelectionChoice selectedChoice = null;
		if ( valueTable.getSelection( ).isEmpty( ) )
		{
			isEnable = false;
		}
		else
		{
			selectedChoice = (SelectionChoice) ( (IStructuredSelection) valueTable.getSelection( ) ).getFirstElement( );