The header of subpages always links to its "superpage", even if it doesn't
exist. I'm not sure if this is a feature or a bug, but I would certainly prefer
that superpages weren't mandatory.

For example, if you are in 'example/page.html', the header will be something
like 'wiki / example / page'. Now, if 'example.html' doesn't exist, you'll have
a dead link for every subpage.

---

This is a bug, but fixing it is very tricky. Consider what would happen if
example.mdwn were created: example/page.html and the rest of example/*
would need to be updated to change the parentlink from a bare work to a
link to the new page. Now if example.mdwn were removed again, they'd need
to be updated again. So example/* depends on example. But it's even more
tricky, because if example.mdwn is modified, we _don't_ want to rebuild
example/*!

ikiwiki doesn't have a way to represent this dependency and can't get one
without a lot of new complex code being added.

For now the best thing to do is to make sure that you always create
example if you create example/foo. Which is probably a good idea anyway..

----

Note that this bug does not exist if the wiki is built with the "usedirs"
option, since in that case, the parent link will link to a subdirectory,
that will just be missing the index.html file, but still nicely usable.
