sympy/sympy — pull request #2901 by skirpichev (2014-02-11 23:28:40+00:00)
Title: log._eval_is_positive: better handling of symbolic assumptions

See example in [this post](https://groups.google.com/d/msg/sympy/J_nB3SzKKAA/aOtjXsJqdIUJ).