How to manipulate the query that fetches products to display on product lists (mainly category page).

[zunxunz]

I need to adapt the query that fetches products for the category page (add a join to a custom table, and some where clauses).

I've tried to find a hook that would allow me to change the query. I did find hookActionProductSearchProviderRunQueryBefore but the $params['query'] in this hook seems to just give the query parameters as set by the faceted search module, and the actual query can't be changed there, nor can I change $params['query'] to add a join and where clauses.

How would I accomplish this?