sympy/sympy — pull request #1533 by oscarbenjamin (2012-09-18 22:07:12+00:00)
Title: Fix typo in return from dup_zz_heu_gcd

This typo can lead to errors when cancelling polynomials. See the added tests for an example that fails.

I found this following the discussion here:
https://groups.google.com/d/msg/sympy/oC8FuQ_yWmo/Dqg3s1h2oXQJ