Add an action at the end of `WP_Query::parse_tax_query()` called (wait for it...) `parse_tax_query` which will enable developers to alter `$this->tax_query->queries` before SQL is generated. `pre_get_posts` is too early for many scenarios.



git-svn-id: https://develop.svn.wordpress.org/trunk@25311 602fd350-edb4-49c9-b593-d223f7449a82