WooCommerce Product Search 6.1.0

* Substantially improved query processing performance with a revised algorithm, fixed overhead in conjunctive term query.
* Added automatic database update path for minor revisions.

* WooCommerce 4.4 compatible.
* Replaced use of deprecated function woocommerce_reset_loop() with wc_reset_loop() when available (as of WC 3.3).
* Noting that previously introduced woocommerce_product_search_query_vars and woocommerce_product_search_query_vars_intersect filters are not used and considered removed.
* Fixed potential database version number update miss and resetting internal table reference to force cache refresh.
* Fixed potential execution time issues when index processing is initiated on the same request as the database update.
* Updated settings HTML to avoid the undesired edit prompt when saving changes.
* Guarded update procedure against inconsistent caching systems like W3 Total Cache and WP Engine's object cache which do not recognize changed options properly.

* This release includes major improvements aimed at further optimizing our search engine's performance and enhancing its search and filtering features.
* WordPress 5.5 compatible.
* WordPress 5.6 (alpha) compatibility tested.
* WooCommerce 4.3 compatible.
* Requires at least WordPress 5.0.
* Requires at least WooCommerce 3.0.
* Enhanced the search engine's indexing features to optimize term handling.
* Added the woocommerce_product_search_process_query_object_term_limit filter.
* Fixed a wrong variable used in category filter when showing parent navigation.
* Fixed an issue with incorrect term counts, due to the wrong variable used in the term count evaluation for hierarchical taxonomies.
* Fixed wrong product counts with variable products and product filters (faceted searches), where certain product filter combinations would show more products related to terms than were actually available.
* Improved search weight handling for product categories so that weights of parent categories are taken into account in their child categories.
* Improved product indexing to sync to changes in terms from product taxonomies.
* Improved search engine performance thanks to optimizations related to object type lookups.
* Added support for role-based performance caching.
* Added the WPS_ROLES_CACHE constant to control role-based caching.
* Added the wps_cache_get() API function (allows override).
* Added support for group-based performance caching with Groups Groups.
* Added the WPS_GROUPS_CACHE constant to control group-based caching.
* Added the wps_cache_set() API function (allows override).
* Introduced fixed and adaptive object limits for scalability trade-offs on very large product sets, where complete result sets are QoS unfeasonable while incomplete result sets are QoS acceptable.
* Added the WPS_OBJECT_LIMIT constant that controls fixed or adaptive object limits, integer for fixed limit, 0 for unlimited, 'AUTO' or 'AUTOREPORT' for adaptive limits.
* Added the WPS_OBJECT_LIMIT_FACTOR constant that controls adaptive object limits.
* Improved price handling queries performance and avoided duplicate queries.
* Reduced rating filter footprint reducing generic queries.
* Fixed issues with on sale and rating filters cancelling each other.
* Solved and improved resilience to interference from other plugins hooked on the shutdown action, affecting our filter responses.
* Added the woocommerce_product_search_shutdown_remove_all_actions filter.
* Solved interference with filter requests from other plugins that hook on the 'query_vars' filter, e.g. WCS adds 'sku' creating a conflict with filter requests for front page shops.
* Added the woocommerce_product_search_query_vars and woocommerce_product_search_query_vars_intersect filters.
* Improved the [woocommerce_product_filter_products] shortcode performance by avoiding duplicate queries that can occur when plugins request page content outside main loop.
* Increased cache lifetime for more dynamic data to 15 minutes.
* Fixed result count string not translated when products shortcode is used.
* Solved issues with unrequired product filter request redirects.
* Fixed pagination link highlight when current page exceeds total page results count.
* Fixed filter request issues for Shops on Front.
* Fixed filter request issues for [woocommerce_product_filter_products] on Front.
* Improved filter request performance and resilience also for unprocessed DOM.
* Added the woocommerce_product_search_get_min_max_price filter.
* Changed the reference for price filters to use lower bounds to determine inclusion in results.
* Added the option to go to page one results on filters applied and made it the default.
* Reduced indexing start on activation.
* Disabled problematic widget caching for now, which conflicts with object caching due to their dynamic content.
* Translations updated.