Unable to set parsed category from custom rewrite parser

During rewrite listener (builder/parser) testing in 5.2.0 (because of large changes to whole application initialization process) I discovered, that code

$params['m_cat_id'] = 15; // no category from url and I need to set a custom one here (won't be affecting <inp2:st_ContentBlock .../>)

doesn't work.

After a little research I discovered that rewrite listener, that searched for a category actually set 0 as current category id, when it wasn't able to find it in url. This wasn't a necessary measure, since m_cat_id variable is set to 0 before url parsing is started anyway.