By using the conditional parser functions #ifeq, #ifexpr or #switch together with #time (or with time-dependent magic words such as CURRENTDAY), a page can be made to parse and render differently at different times. However, the link tables (pagelinks, imagelinks, templatelinks and categorylinks) will only contain links that were present when the page was parsed.
This is closely related to bug 14404, but I'm filing this separately since the proximate cause is different, and since I suspect they'll need separate fixes.
I particular, this can cause cascading protection to fail unexpectedly if such time-dependent conditionals are used on the protected page. Of course, the workaround is to just not do that, but not all users may know that. (And, unfortunately, many of the pages most likely to need cascading protection are also the ones most likely to benefit from time-dependent parsing.)
Version: 1.15.x
Severity: minor
URL: http://commons.wikimedia.org/w/index.php?title=Commons:Village_pump&oldid=20274720#Cascading_protection_broken.3F
See Also:
https://bugzilla.wikimedia.org/show_bug.cgi?id=57256