Bug 145520 Group name will not show up in group list if the group use default name and key expression has no value
Description: Group name will not show up in group list if key expression has no value. Steps to reproduce: 1. Insert a table into report, bind it to a data set 2. Switch to property editor -> groups 3. Click on add button to open new group dialog, then press ok button Expected result: A new group with default name will be added to group list Actual result: A new group is added to group list, but without group name. But when let group tab lost focus and get focus again, you can see the group name.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/command/ContentCommand.java
if ( !element.getDefn( ).isContainer( ) )
			throw new ContentException( element, slotID,
					ContentException.DESIGN_EXCEPTION_NOT_CONTAINER );
		ContainerSlot slot = element.getSlot( slotID );
		if ( slot == null )
			throw new ContentException( element, slotID,
					ContentException.DESIGN_EXCEPTION_SLOT_NOT_FOUND );
		if ( !slot.contains( content ) )
			throw new ContentException( element, slotID, content,
					ContentException.DESIGN_EXCEPTION_CONTENT_NOT_FOUND );
		if ( !slot.canDrop( content ) )
			throw new ContentException( element, slotID, content,
					ContentException.DESIGN_EXCEPTION_DROP_FORBIDDEN );
		
		
		if ( !content.canDrop( ) && !flag )
			throw new ContentException(
					element,
					slotID,
					content,
					ContentException.DESIGN_EXCEPTION_STRUCTURE_CHANGE_FORBIDDEN );
		
		
		if ( hasDescendents( content, slotID ) )
		{
			throw new ContentException( element, slotID,
					ContentException.DESIGN_EXCEPTION_HAS_DESCENDENTS );
		}
		
		ContentRecord dropRecord = new ContentRecord( module, element, slotID,