Emitting UTF-8 chars >= 0xD800 in JS map stops design doc from indexing

Was trying determine UTF-8 Char collation, using the following Gist: https://gist.github.com/1904807

It turns out that once the view gets to the document that would emit "\uD800", the view server times out and stops indexing that design document.

This seems like a bug, since I can 'store' a document with UTF-8 chars >= 0xD800, but one cannot emit a key with that char in the string.