qalculate makes mistakes in factoring

Binary package hint: qalc

Open a terminal and perform the following:

$ qalc
> (1-y^(-2x))/(2x)+(-(-2xy^(-2x)-y^(-2x))/(x^2)-(-3xy^(-3x)-y^(-3x))/(x^2))-(y^(-2x)-y^(-3x))/(x)+5(y^(-3x)-y^(-6x))/(x)-((x^2(9xy^(-3x)+3y^(-3x))-2x(-3xy^(-3x)-y^(-3x)))/(x^4)+(x^2(36xy^(-6x)+6y^(-6x))-2x(-6xy^(-6x)-y^(-6x)))/(x^4))

  warning: To avoid division by zero, the following must be true: x != 0.
  error: factorized result is wrong: -82x^2 + x^2 + x + -16x + -36x + 2x + -4 + -4. This is a bug. Please report it.
  warning: To avoid division by zero, the following must be true: x != -(+infinity) / ln(y).
  ((1 - (y^(-(2 * x)))) / (2 * x)) + (((-((-(2 * x * (y^(-(2 * x))))) - (y^(-(2 * x))))) / (x^2)) - (((-(3 * x * (y^(-(3 * x))))) - (y^(-(3 * x)))) / (x^2))) - (((y^(-(2 * x))) - (y^(-(3 * x)))) / x) + ((5 * ((y^(-(3 * x))) - (y^(-(6 * x))))) / x) - (((((x^2) * ((9 * x * (y^(-(3 * x)))) + (3 * (y^(-(3 * x)))))) - (2 * x * ((-(3 * x * (y^(-(3 * x))))) - (y^(-(3 * x)))))) / (x^4)) + ((((x^2) * ((36 * x * (y^(-(6 * x)))) + (6 * (y^(-(6 * x)))))) - (2 * x * ((-(6 * x * (y^(-(6 * x))))) - (y^(-(6 * x)))))) / (x^4))) = -(81x^2 + 49x + 8) / (2x^3)

This is not in the upstream bug tracker.