dotnet/corefx — pull request #140 by KrzysztofCwalina (2014-11-21 23:35:33+00:00)
Title: Allow null comparer to be passed to Sort

Sort methods on Array, List, and other collections accept null comparers. This is not the case for immutable collections, despite what the doc comments claim. This change fixes the inconsistency buy allowing null comparers being passed to Sort methods of the immutable collections.