Re: [Qemu-devel] [PATCH] hw/usb/bus.c: print device ID when 'info usb' used

[Gerd Hoffmann]

On Fr, 2015-08-28 at 09:39 -0400, Programmingkid wrote:
> On Aug 28, 2015, at 9:35 AM, Daniel P. Berrange wrote:
> 
> > On Fri, Aug 28, 2015 at 09:08:12AM -0400, Programmingkid wrote:
> >> 
> >> On Aug 28, 2015, at 7:50 AM, Gerd Hoffmann wrote:
> >> 
> >>> On Mo, 2015-08-24 at 15:13 -0400, Programmingkid wrote:
> >>>> +            monitor_printf(mon, "  Device %d.%d, Port %s, Speed %s
> >>>> Mb/s,"
> >>>> +                                "Product %s, ID %s\n",
> >>>> +                           bus->busnr, dev->addr, port->path,
> >>>> +                           usb_speed(dev->speed),
> >>>> +                           dev->product_desc, dev->qdev.id);
> >>>> 
> >>> 
> >>> dev->qdev.id can be NULL.
> >>> 
> >>> cheers,
> >>> Gerd
> >> 
> >> That isn't a problem. It will just say "null" when it is printed.
> >> No crash or garbage text.
> > 
> > Handling of '%s' with NULL is undefined by the standard. Linux
> > glibc prints the string "null", but other implementations can
> > crash.
> 
> "null" is also printed on Mac OS X. 
> 
> Do you want dev->qdev.id replaced with this? (dev->qdev.id != NULL) ? 
> dev->qdev.id : "null"

Even better: Don't print "ID: ..." in the first place in case it is not
present.

cheers,
  Gerd