adienes
```julia julia> f(x::Union{Nothing, S}) where {S} = @isdefined(S) ? S : false f (generic function with 1 method) julia> g(r) = f(r[]) g (generic function with 1 method) julia> g(Ref{Any}(nothing)) svec(S, false) # 1.14 false # 1.13 ``` regression from https://github.com/JuliaLang/julia/pull/61645