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
}
				else
				{
					for ( int i = 0; i < columnList.size( ); i++ )
					{
						if ( groupKey.equals( DEUtil.getExpression( columnList.get( i ) ) ) )
						{
							index = i;
							break;
						}
					}
				}
			}
			String oldKeyExpr = inputGroup.getKeyExpr( );
			String newKeyExpr = getKeyExpression( );
			inputGroup.setKeyExpr( newKeyExpr );
			if ( newKeyExpr != null
					&& newKeyExpr.length( ) != 0
					&& !newKeyExpr.equals( oldKeyExpr )
					&& index != -1 )
			{
				SlotHandle slotHandle = null;
				
				if ( inputGroup instanceof ListGroupHandle )
				{
					slotHandle = inputGroup.getHeader( );
					
					
				}
				else if ( inputGroup instanceof TableGroupHandle )