networkx/networkx — pull request #937 by chebee7i (2013-08-25 05:27:04+00:00)
Title: Line graph algorithm doesn't handle self-loops correctly

The algorithm in line_graph() doesn't capture self-loops correctly.
See the discussion and code examples at
http://stackoverflow.com/questions/18214305/correctness-of-networkx-line-digraph-construction/18244242