im working on building shop with Presta, I have problem with previous button in pagination at category page, it always adds something to href, it wouldn't be a problem but i wrote javascript to operate things like changing products per page or category filters by changing links.

Lets say my actual link is something like

localhost/index.php?id_category=10&controller=category?resultsPerPage=18&page=2

Normally previous button should have href to

localhost/index.php?id_category=10&controller=category?resultsPerPage=18

But in my case it has href to

localhost/index.php?id_category=10&controller=category?resultsPerPage=18y

I tried to make js script to slice last letter from href, but it just doesnt work, there's always something added to this href, letter isn't problem it just looks weird but site as far as i tested works fine, but if it is digit it can result in change properties of for example resultsPerPage. I wonder if its a problem with Pagination.php and its' link building method, because in my scripts i have nothing that could couse this problem, maybe anyone had same problem and knows any solution?