Created attachment 65071 [details] ScreenShot1 Steps to recreate. 1.Check and make sure UseQueryParser system preference is set to "Don't Try" 2.Preform a search in koha. 3.From an items detail page click on a subject heading. 4.Koha will return results. Next - Turn on UseQueryParser and follow same steps. This will cause Koha to break.
I can reproduce this bug when UseICU is also on. Among other effects, UseICU will use {} rather than "" to quote a subject phrase when building the subject headings link (see bug 7092). However, a search like su:{Cats} triggers an infinite loop bug in OpenILS::QueryParser->decompose(). The following warnings emitted by QueryParser with debug logging turned on gives an idea of what's going on: Start of the loop. last_type: , joiner: &, struct: Koha::QueryParser::Driver::PQF::query_plan=HASH(0x40e1618) Encountered class change: subject|subject#su Start of the loop. last_type: , joiner: &, struct: Koha::QueryParser::Driver::PQF::query_plan=HASH(0x40e1618) Encountered atom: {Wizards Remainder: } Start of the loop. last_type: , joiner: &, struct: Koha::QueryParser::Driver::PQF::query_plan=HASH(0x40e1618) Start of the loop. last_type: , joiner: &, struct: Koha::QueryParser::Driver::PQF::query_plan=HASH(0x40e1618) Start of the loop. last_type: , joiner: &, struct: Koha::QueryParser::Driver::PQF::query_plan=HASH(0x40 ... above repeats indefinitely This bug appears to be more or less identical to one of the issues fixed by Evergreen bug https://bugs.launchpad.net/evergreen/+bug/1251359.
We've voted to remove the QueryParser code (https://wiki.koha-community.org/wiki/Development_IRC_meeting_4_March_2020), so I am closing this WONTFIX.