BIND started replying to queries for .com with .COM

[Mark Andrews]

In message <56FBBE83.6080701 at imperial.ac.uk>, Phil Mayers writes:
> On 30/03/2016 12:25, Mark Andrews wrote:
> 
> > The recent change was to record and return the learnt case of
> > ownernames (to the RRset level) rather than use whatever was used
> > to build the red-black tree names.
> 
> What is considered the source of the ownername for, say, "com."? One 
> thing I saw when I was trying to understand this was the results of the 
> following queries to a cold-cache bind process:
> 
> dig @localhost www.microsoft.CoM
> dig @localhost www.google.com
> dig @localhost www.google.com
> 
> I was surprised that #2 and #3 auth/add sections contain the .CoM label 
> presumably built from #1, and also that #2 and #3 answer sections differ.
> 
> None of this is a problem, but I am curious and I couldn't figure it out 
> from the code!

Sorry, I forgot, the recording of ownercase is in 9.11 (required
new db method which is why it wasn't back ported).  9.10 still uses
the rbt case.  This preserves the in zone labels assuming the
authoritative server preserves the learnt case.

I've been using 9.11.0pre-alpha for too long.  This has advantages
(I discover bugs in new code first) and disadvantages (you aren't
running exactly what everyone else is and occassionaly you forget
that a feature isn't yet available).  I think the advantages outweigh
the disadvantages most of the time.

That said anything matching ownernames should be doing this case
insensitively.

Mark
-- 
Mark Andrews, ISC
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742                 INTERNET: marka at isc.org