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
{
		keyChooser.deselectAll( );
		key = StringUtil.trimString( key );
		if ( StringUtil.isBlank( key ) )
		{
			keyChooser.setText( "" ); 
			return;
		}
		for ( int i = 0; i < columnList.size( ); i++ )
		{
			if ( key.equals( DEUtil.getExpression( columnList.get( i ) ) ) )
			{
				keyChooser.select( i );
				return;
			}
		}
		keyChooser.setText( key );
	}
	/**
	 * Reset interval
	 * 
	 */
	private void resetInterval( )
	{
		String currentKeyExpression = keyChooser.getText( );
		if ( previoiusKeyExpression.equals( currentKeyExpression ) )
			return;
		if ( ExpressionUtility.isColumnExpression( currentKeyExpression ) )
			intervalChoices = getSubIntervalChoice( );
		else