Before this change, when attempting to integrate a
piecewise function (or a function that internally
gets converted to a piecewise function
(like 1/Abs(x)), if some part of the
function on some interval evaluates to
some type of infinity at an endpoint of
the interval it could result in the indefinite
integral containing an added infinity or being nan
on that interval. This change fixes this issue.

Example

In [1]: from sympy import *

In [2]: x = Symbol('x', real=True)

In [3]: integrate(1/Abs(x))

Out [3]: Piecewise((-log(x), x <= 0), (log(x), True))

Before this change, integrate(1/Abs(x)) resulted in
Piecewise((-log(x), x <= 0), (nan, True))