BIND 10 #2427: support $ORIGIN in dns::MasterLoader

[BIND 10 Development]

#2427: support $ORIGIN in dns::MasterLoader
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            Reporter:  jinmei        |                        Owner:
                Type:  task          |  jinmei
            Priority:  medium        |                       Status:
           Component:  libdns++      |  reviewing
            Keywords:                |                    Milestone:
           Sensitive:  0             |  Sprint-20121218
         Sub-Project:  DNS           |                   Resolution:
Estimated Difficulty:  3             |                 CVSS Scoring:
         Total Hours:  0             |              Defect Severity:  N/A
                                     |  Feature Depending on Ticket:
                                     |  loadzone-ng
                                     |          Add Hours to Ticket:  0
                                     |                    Internal?:  0
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Comment (by jinmei):

 In terms of merge-readiness, it basically looks okay with one final
 comment: if I read it correctly this code warns if the first name
 in an included file is omitted:

 {{{
 a.example.com. IN A 192.0.2.1
 $INCLUDE <some file>; begins with '   IN A 192.0.2.2'
 }}}

 then it warns about it with "Ambiguous previous name for use in place
 of initial whitespace" (there was a duplicate "previous name" in your
 original version, which I removed).  The behavior is compatible with
 BIND 9, so it looks okay, but I'd explicitly test the case.  Also,
 since in this case it's not really (or necessarily) "ambiguous", we
 might revisit the warning message, e.g, "owner name is omitted with an
 initial whitespace around $INCLUDE; the result may not what was intended".
 But I'd leave it to you.

 I'll respond to other non-blocking discussion points later.

-- 
Ticket URL: <http://bind10.isc.org/ticket/2427#comment:15>
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