[Koha] Linking via 830$w

[Thomas Klausner]

Hi!

We have encountered an interesting behaviour and are not sure if it's a 
bug in Koha, in our data, or something else:

We have a bibliographic record A where 830$w points to another record B 
(to the other records' 001 value, to be precise):

A: 830$w = 12345
B: 001 = 12345

When Koha renders record A, it produces a link to B, but with a bad param:
http://intranet/cgi-bin/koha/catalogue/search.pl?q=rcn:12345

Changing the param from 'rcn' to 'control-number' finds the correct record:
http://intranet/cgi-bin/koha/catalogue/search.pl?q=control-number:12345

We're using ElasticSearch with default mappings. Looking into those, I 
see that there are defintions for record-control-number (rcn) and 
control-number.

control-number points to 001, and rcn to various 7/8nn$w fields. Now it 
makes sense that the search for rcn did not find the value stored in 
record B.001, and why chaning the search to control-number finds the 
record.

Which leads to my question;

* Should we add 001 to the fields mapped to record-control-number?

* Should we use a different field than 830w$?
  We are quite sure that we shouldn't, as the DNB is also using 830$w:
  https://portal.dnb.de/opac/simpleSearch?query=9783847703389 
  "Beziehungen: Die Andere Bibliothek ; Bd. 338", linking to 
  (DE-101)015935620:
  https://portal.dnb.de/opac/opacPresentation?cqlMode=true&reset=true&referrerPosition=0&referrerResultId=%229783847703389%22%26any&query=idn%3D015935620

* Should we change the template to produce a link using a different 
  param? Feels wrong, becuase it does make sense to link to 'rcn' and 
  not to 'control-number'. Also we don't want to mess with the core Koha
  templates...

Any ideas / pointers?

Greetings,
domm

-- 
#!/usr/bin/perl                             https://domm.plix.at
for(ref bless{},just'another'perl'hacker){s-:+-$"-g&&print$_.$/}