Comments 43-51 identified a further problem with unconditionally coding
a newly auto-created authority's 008/11 (and 040$f) from the source bib
heading's thesaurus: when LinkerConsiderThesaurus is off (the default),
the linker matches new headings to existing authorities by text alone,
regardless of thesaurus. So a bib heading from one thesaurus (e.g. FAST)
can auto-create an authority coded for that thesaurus, and a later bib
heading with the *same* text but no thesaurus of its own (or a different
one) can then link to that same authority purely on the text match.
Saving that authority afterwards propagates its 008/11 and 040$f coding
back onto every bib heading linked to it - silently adding indicators and
subfields the cataloguer never set, on installs that never opted into
thesaurus-aware behaviour.
Before this bug, AutoCreateAuthorities always created LCSH-coded records,
so that propagation was always onto the coding most sites already expect.
This bug's earlier patches changed that default for every site regardless
of whether they use LinkerConsiderThesaurus, which is what comments 43/45
(reproduced by Pedro Amorim) demonstrated as disruptive.
Sites that haven't turned on LinkerConsiderThesaurus don't benefit from
thesaurus-aware authority creation anyway, since their linker never
searches by thesaurus - C4::Heading::_search and C4::Linker::Default
already gate thesaurus-consideration on this same preference for
matching. This change gates authority-creation coding on it too, so the
behaviour introduced by this bug only applies to installs that already
opted into thesaurus-aware linking.
Test plan:
1. prove t/db_dependent/Biblio.t
Note the new case 7 in the "codes new authorities with the source
thesaurus" subtest: with LinkerConsiderThesaurus off, a FAST heading
no longer codes the new authority as FAST, it keeps the
MARCAuthorityControlField008 syspref default instead.
2. Librarian-facing regression check: with LinkerConsiderThesaurus off
(the default), AutoLinkBiblios and AutoCreateAuthorities on, catalogue
a 650 with ind2=7 $2=fast and save. The new authority's 008/11 should
be whatever MARCAuthorityControlField008 says (LCSH 'a' by default),
not 'z'.
3. Confirm the LinkerConsiderThesaurus=on cases from the earlier patches
are unaffected: with it on, a FAST heading still codes 008/11='z' with
040$f=fast, and a MeSH heading still codes 008/11='c'.
Sponsored-by: Heythrop Library <https://heythroplibrary.co.uk/>
Signed-off-by: Phil Ringnalda <phil@chetcolibrary.org>
Signed-off-by: David Cook <dcook@prosentient.com.au>
Signed-off-by: Pedro Amorim <pedro.amorim@openfifth.co.uk>
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