Thread safety fix: use shared_ptr<Searcher> internally when performing searches, instead of Searcher directly, so Searcher not released by some other thread while still being used.
Thread safety fix: use shared_ptr<Searcher> internally when performing searches, instead of Searcher directly, so Searcher not released by some other thread while still being used.

Blue-Rocket/BRFullTextSearch,Blue-Rocket/BRFullTextSearch,Blue-Rocket/BRFullTextSearch,Blue-Rocket/BRFullTextSearch