Bug 30280 taught the linker that "650 _ 0 $aFeminism" and "650 _ 7 $aFeminism$2sao" are not the same heading, so a bib record containing the latter should not be linked to the authority record which matches the former.

However, AutoCreateAuthorities just creates LCSH authority records from anything, no matter what the values of indicator 2 and subfield 2 are.

As a result, if you have an LCSH authority record for a term, and you import/create a non-LCSH term in a bib record and save it, AutoCreateAuthorities will create a new duplicate LCSH authority record and link to that. Every single time, a new duplicate.

Steps to reproduce:

1. Use ElasticSearch, since the patch for bug 30280 only expected to work there, and in fact broke linking on Zebra, bug 31924.
2. Enable the preferences AutoCreateAuthorities, AutoLinkBiblios, CatalogModuleRelink
3. Edit any bib record, add a 650 tag, set the second indicator to 7, type Feminism in subfield a and type sao in subfield 2.
4. Save the record, edit it again, note the authority record id in subfield 9 of the Feminism heading.
5. Edit any other bib record, add a 650 tag, set the second indicator to 7, type Feminism in subfield a and type sao in subfield 2.
6. Save the record, edit it again, note the authority record id in subfield 9 of the Feminism heading.

The two authority record ids should be the same, since the headings are identical, but instead one will be linked to, say, 1708 and the next to 1709, an identical duplicate record. Rather than setting position 11 of field 008 in the authority record to "a" for LCSH, AutoCreateAuthorities should have set it to "z" for Other and put sao in subfield f of field 040 (and for non-7, non-0 values of indicator 2, it should be setting 008/11 to the correct letter for that indicator value).