Bug 183308 IllegalArgumentException occurs after insert a empty group on a List report item[0001]
Description: IllegalArgumentException occurs after insert a empty group on a List report item[0001] Build number: 2.2.0.v20070419-0945 Steps to reproduce: 1, Insert a list 2, Insert a group on the list, only specify the Group On: "aa" Expected result: No exception Actual result: IllegalArgumentException occurs Error log: java.lang.IllegalArgumentException: Argument cannot be null at org.eclipse.swt.SWT.error(SWT.java:3483) at org.eclipse.swt.SWT.error(SWT.java:3422) at org.eclipse.swt.SWT.error(SWT.java:3393) at org.eclipse.swt.widgets.Widget.error(Widget.java:432) at org.eclipse.swt.widgets.Text.setText(Text.java:1793) at org.eclipse.birt.report.designer.ui.dialogs.GroupDialog$6.focusLost(GroupDialog.java:485) at org.eclipse.swt.widgets.TypedListener.handleEvent(TypedListener.java:136) at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:66) at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:938) at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:962)
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/ui/dialogs/GroupDialog.java
if ( inputGroup.getName( ) != null )
		{
			nameEditor.setText( inputGroup.getName( ) );
		}
		if ( inputGroup.getBookmark( ) != null )
		{
			bookmarkEditor.setText( inputGroup.getBookmark( ) );
		}
		refreshColumnList( );
		setKeyExpression( inputGroup.getKeyExpr( ) );
		PropertyHandle property = inputGroup.getPropertyHandle( GroupElement.INTERVAL_RANGE_PROP );
		String range = property == null ? null : property.getStringValue( );
		intervalRange.setText( range == null ? "" : range ); 
		int index = getIntervalTypeIndex( inputGroup.getInterval( ) );
		intervalType.select( index );
		if ( index == 0 )
		{
			intervalRange.setEnabled( false );
			intervalBaseButton.setEnabled( false );
			intervalBaseText.setEnabled( false );
		}
		else
		{
			intervalRange.setEnabled( true );
			if ( getColumnType( ) == String.class )
			{
				intervalBaseButton.setEnabled( false );
				intervalBaseText.setEnabled( false );
			}
			else