To reproduce the bug, just create a page with {{PAGESIZE: foo }} and open it in edit mode. MediaWiki 1.17 and 1.18 shows [[foo]] as if it were one of the templates in the page (which has no template at all). For a real example, see
https://pt.wikipedia.org/w/index.php?title=Wikipédia:Concursos/I_GP_Wikimedia_Brasil/Lista&action=edit&uselang=en
That page should display only [[Template:artigo6]] in the list.
Version: unspecified
Severity: normal
URL: https://pt.wikipedia.org/w/index.php?title=Wikipédia:Concursos/I_GP_Wikimedia_Brasil/Lista&action=edit&uselang=en