Category pagination — cannot return to page 1 when SEF enabled (limitstart lost, session retains last page)
Version: VirtueMart 4.6.8 (11258), Joomla 5.4.6, PHP 8.x, Joomla core SEF enabled (no third-party SEF/router)
Summary:
On a category with more than one page of products, navigating to page 2 and then clicking the "1" (or "Start"/"Prev") pagination link does not return the visitor to page 1. The page reloads still showing page 2.
Steps to reproduce:
Enable Joomla SEF URLs.
Open a category with 2+ pages of products (default limit, e.g. 12 per page).
Click "2" — URL becomes /category/results,13-24, page 2 displays correctly.
Click "1" (or « / ‹).
Observed: browser navigates to the bare category URL /category and page 2 is still shown.
Expected: page 1 is displayed.
Root cause (traced):
Two interacting pieces of core code:
In administrator/components/com_virtuemart/models/product.php (setPaginationLimits), when the visitor is already within the same category/manufacturer, limitStart is read via getUserStateFromRequest() against a per-category session key (com_virtuemart.<view>c<cateid>m<manid>.limitstart). This only overrides the stored session value if limitstart is explicitly present in the request.
In components/com_virtuemart/router.php, the build routine only emits a results,X-Y segment when limitstart > 0. For page 1 (limitstart = 0) no segment is added, so the page-1 pagination link is generated as the bare category URL. Joomla's SEF router additionally strips limitstart=0 as it equals the default.
Result: the page-1 link carries no page position. When it loads, getUserStateFromRequest() finds no limitstart in the request and falls back to the session value, which still holds the offset for page 2 — so the visitor is stuck on page 2.
Note: This only reproduces with an active session already advanced past page 1. A fresh/cookieless request to /category/results,1-12 returns page 1 correctly, which is why it can look intermittent.
Suggested fix direction:
Either (a) have the router emit an explicit results,1-N segment for limitstart = 0 so the page-1 link isn't collapsed to the bare URL, or (b) in the category model, treat a request with no limitstart/start parameter as page 1 rather than inheriting the stored session offset.