Symbolic integration gives result with wrong sign (integrand is positive):
sage: z = integrate(log(1 + 1/(x**2 + 1)), x, -oo, oo); z
2*pi - 2*sqrt(2)*pi
sage: z.n()
-2.60258056913715
sage: numerical_integral(log(1 + 1/(x**2 + 1)), -oo, oo)
(2.6025805691369728, 5.127078281515988e-10)
Sage 8.3
