sympy/sympy — pull request #7583 by skirpichev (2014-06-10 16:57:50+00:00)
Title: Shift two issue numbers (see #7579)

I'm still not sure about #4087. The patch a945bc6 was introduced in #4021, issue #4087 was mentioned in this bugreport. Maybe it's a typo (998 vs 988).

@fredrik-johansson