Broken promotions

[8d1h]

I updated Singular and some promotions are broken
https://github.com/8d1h/IntersectionTheory/runs/3060958843?check_suite_focus=true

julia> Singular.Nemo.QQ(1) * Singular.PolynomialRing(Singular.QQ, ["a"])[2][1]
ERROR: Cannot promote to common type
Stacktrace:
 [1] *(x::Nemo.fmpq, y::spoly{n_Q})
   @ AbstractAlgebra ~/.julia/packages/AbstractAlgebra/hlSYb/src/Rings.jl:83

I guess this is due to Nemocas/AbstractAlgebra.jl#927

[thofma]

Thanks for the report. I will have a look.

[thofma]

Where do you need this? I am a bit hesitant to add it.

[8d1h]

It's just for convenience (and it worked before...) I can always add it manually in my package.

Also coercion works already so it makes sense to allow promotion

julia> R = Singular.PolynomialRing(Singular.QQ, ["x"])[1];

julia> R(Singular.Nemo.QQ(1//2))
1//2

[thofma]

Yes, I understand. If we add a promote rule, it will be called automatically. For fmpq and spoly{n_Q} it is fine, but do you also want fmpq and n_Q? I am not sure want this, because it is not clear what the type of the result should be.

[8d1h]

I agree. fmpq and n_Q should not be allowed. (I just saw the code for spoly promotion...)