google/souper — pull request #19 by regehr (2014-06-17 06:52:20+00:00)
Title: fix null pointer crash

Souper was crashing when invoked like this:

souper foo.bc

The problem was that when the solver command line argument was missing, a Solver
object with a NULL BaseSolver was getting created, crashing later on. The fix is
to avoid creating the Solver and just return NULL when we don't have a
BaseSolver.