When browsing a category with over 400 pages backwards (from "next" page to "previous") incorrect link to previous page appears. In effect some pages are ommited inlistings.
Testcase:
- Open http://test.wikipedia.org/w/index.php?title=Category:Category_with_many_files and click "next 200" twice (on this and next page)
- When you see pages: Page401 to Page600, click "previous 200"
- You see a page with links to Page201 to Page400, and link to "previous 200" on that page is incorrect: it points to http://test.wikipedia.org/w/index.php?title=Category:Category_with_many_files&pageuntil=Page200#mw-pages instead of http://test.wikipedia.org/w/index.php?title=Category:Category_with_many_files&pageuntil=Page201#mw-pages
(pageuntil should should be set to the first element of current page, not the previos one)
- If you click the "previous 200" link, you see links to Page001 to Page199. the Page200 is omitted.
The "pageuntil=" parameter in a link seems to be the source of the problem. This effect appears on pages generated in backward browsing by clicking the "previous 200" link, when the "pageuntil=" parameter is used. On any wiki. A category must contain at least 401 pages to observe this effect.
Version: 1.20.x
Severity: normal