further fixes for I=R situation

Author: ederc

src/algorithms/solvers.jl

@@ -131,7 +131,8 @@ function _core_msolve(
     nterms  = 0
 
     if jl_dquot == 0
-        I.rat_param = RationalParametrization(Symbol[], fmpz[], fmpq_poly(-1), fmpq_poly(-1), PolyElem[])
+        C,x = PolynomialRing(QQ,"x")
+        I.rat_param = RationalParametrization(Symbol[], fmpz[], C(-1), C(-1), PolyElem[])
         I.real_sols = fmpq[]
         return I.rat_param, I.real_sols
     end

src/types.jl

@@ -45,6 +45,5 @@ end
 Base.parent(I::Ideal) = Nemo.parent(I.gens[1])
 
 Base.show(io::IO, I::Ideal) = print(io, I.gens)
-Base.show(io::IO, R::RationalParametrization) = R.vars == Symbol[] ? print(io, "Solution set is empty.") : print(io, R)
 
 Base.getindex(I::Ideal, idx::Int) = I.gens[idx]