Re: [DRAFT 1/1] lib: replace some uses of Query::MatchAll with a thread-safe alternative

Kevin Boulain writes: > This is what can be expected from the tests when they fail: >== stderr == > +== > +WARNING: ThreadSanitizer: data race (pid=207931) > + Read of size 1 at 0x7b1001a0 by thread T2: > +#0 memcpy (libtsan.so.2+0x62506) > +#1 void std

[DRAFT 1/1] lib: replace some uses of Query::MatchAll with a thread-safe alternative

This replaces two instances of Xapian::Query::MatchAll with the equivalent but thread-safe alternative Xapian::Query(std::string()). Xapian::Query::MatchAll maintains an internal pointer to a refcounted Xapian::Internal::QueryTerm. None of this is thread-safe but that wouldn't be an issue if Xapia