Reporter: a.t.chadwick[at]gmail.com
[Submitted to the original trac issue database at 10.07pm, Tuesday, 10th June 2008]

I recently tagged a new landuse=residential (20175534) completely encircling an existing leisure=common (24777545) and set up a new multipolygon relation (16272) between the two objects, setting them as outer and inner respectively. See the map URL below for a quick overview. If you're looking at histories, ignore the revision at 2008-06-11T10:34:26+01:00, that's just me being a muppet with Potlatch.

The current multipolygon recommendation in the wiki says:

They can also be tagged as appropriate for the content of the respective holes.
http://wiki.openstreetmap.org/index.php/Relations/Multipolygon

And that's what I've done. Osmarender copes with this reasonably, but the Mapnik layer renders the outer ring in "leisure=common" green, with a blank hole in the middle:

http://www.openstreetmap.org/?lat=51.70607&lon=-1.31916&zoom=16&layers=B00FT

I expected to see an outer ring of "residential grey" and an inner circle of "common green" because that is what the data said at the time.

I will update the wiki to reflect Mapnik's behaviour here, linking to this ticket.

(Note that I'm likely to change this example to be represented as a common inside a separate inner+outer multipolygon fairly soon - because it strikes me as cleaner data rather than because it might render better! A test case can be built from the histories of the 3 objects I mentioned using their state at or before 2008-06-08T20:50:04+01:00).