If an inlined page itself contains an inline directive, the nested directive will produce no output. In [this example wiki](http://www.willthompson.co.uk/tmp/ikiwiki-nested-inline/), the following pages exist:
* _pets_: contains some content, and the directive `inline pages="pets/* and !pets/*/*"` to inline its immediate children.
* _pets/dogs_: some content, and `inline pages="pets/dogs/*"`.
When rendered, _pets_ [contains](http://www.willthompson.co.uk/tmp/ikiwiki-nested-inline/output/pets/) the content from _pets/dogs_ and _pets/cats_, but not the pages inlined into them. However, the subpages [correctly](http://www.willthompson.co.uk/tmp/ikiwiki-nested-inline/output/pets/dogs/) [include](http://www.willthompson.co.uk/tmp/ikiwiki-nested-inline/output/pets/cats/) their own children.
This used to work in at least ikiwiki 1.45. I stepped through `preprocess_inline`, but couldn't see why this wasn't working.
