On Wed, Jun 06, 2012 at 08:46:37AM +0200, Anders Broman wrote:
> Joerg Mayer skrev 2012-06-05 21:52:
> >On Thu, Apr 05, 2012 at 08:38:26AM +0000, etxrab@xxxxxxxxxxxxx wrote:
> >>http://anonsvn.wireshark.org/viewvc/viewvc.cgi?view=rev&revision=41952
> >>
> >>User: etxrab
> >>Date: 2012/04/05 01:38 AM
> >>
> >>Log:
> >> Use common code to add ip version to the tree.
> >>
> >>Directory: /trunk/epan/dissectors/
> >> Changes Path Action
> >> +8 -4 packet-ip.c Modified
> >> +2 -0 packet-ip.h Modified
> >> +1 -18 packet-ipv6.c Modified
> >I strongly disagree with this patch and the patch doing the same to dscp
> >(and the corresponding bug):
> >
> >It completely violates the principle of least surprise: Previous to this
> >patch *all* filterable elements of the ipv6 protocol had filters starting
> >with ipv6. - this is no longer the case. The reason we have the ip_version
> >in ipv6 *in addition to* ipv6_version was exactly this: Some people might
> >be surprised if ip.version==6 would not work - principle of least surprise
> >again.
> >
> >I'm very much for reverting r41952 and r41953 - so much so that I will do
> >exactly this if there are no strong arguments to not do this.
> If I remember correctly the user complaining about this was
> surprised that clicking on ip.version in an IPv4
> packet and doing prepare as a filter and changing the value to 6 got
> no IPv6 packets match in a mixed Ipv4 Ipv6
> trace.
This is very weird, bacause the ipv6_version field could be filtered with
ip.version and ipv6.version before the patch. Looks to me that something
else was wrong.
> I fail to see the importance of every field name without
> exception adhering to the rule of being prefixed
> with "protoname". To me this is a legitimate exception.
Well, if we do an exception there should be good reasons for this and it
should be documented in the source. I fail to see good reasons in both
cases. I reopened the dscp bug to see whether the reporter and patch author
has some good reasons - the already given ones are not IMO - breaking
consistency for convenience in some "corner cases" rarely is good design.
ciao
Jörg
--
Joerg Mayer <jmayer@xxxxxxxxx>
We are stuck with technology when what we really want is just stuff that
works. Some say that should read Microsoft instead of technology.
