SciTools/iris — pull request #1152 by bjlittle (2014-06-02 21:09:04+00:00)
Title: Merge nan fill_value.

This PR enables cube merge to correctly categorise a matching candidate cube with a `fill_value` of `numpy.nan` within a `ProtoCube` also with a `fill_value` of `numpy.nan`.

Previously, merge made an simple equality comparison between `fill_value`s, which of course is incorrect when considering the equality of two `numpy.nan` values.