ucb-bar/chisel — pull request #149 by palmer-dabbelt (2014-03-06 01:20:27+00:00)
Title: Check for NULL file descriptors before close()

I have no idea why this is happening, but I get some SEGVs when trying
to run some code under the test harness. I figured I'd just be
explicit and test for NULL pointers. This appears to have made the
failures go away, but they were sporadic so who knows.