Bug in solving quadratic equations
I would like to use the QuadraticForm solve() method to find vectors of given length in root lattices. Unfortunately this method often produces the answer 0.
A minimal example: to find a vector in the E8 lattice of length two:
QuadraticForm(QQ, CartanMatrix(['E', 8])).solve(2)
yields
(0, 0, 0, 0, 0, 0, 0, 0)