Foo(Foo()) is a stackoverflow on 0.7

[cstjean]

julia> @with_kw struct Foo
       x=1
       y=2
       end
Foo

julia> Foo(Foo())
ERROR: StackOverflowError:
Stacktrace:
 [1] convert(::Type{Array{Union{},1}}, ::Array{Union{},1}) at /home/r2/.julia/packages/ShiftedArrays/psVhR/src/offset.jl:2
 [2] Base.Generator{Array{Union{},1},getfield(ShiftedArrays, Symbol("##35#36")){Tuple{}}}(::Function, ::Array{Union{},1}) at ./generator.jl:32 (repeats 2 times)
 ... (the last 2 lines are repeated 26665 more times)
 [53333] convert(::Type{Array{Union{},1}}, ::Array{Union{},1}) at /home/r2/.julia/packages/ShiftedArrays/psVhR/src/offset.jl:2

It worked fine on 0.6

[mauro3]

I cannot reproduce on neither 0.7 nor 1.0:

julia> using Parameters                                                                                                                                      
                                                                                                                                                             
julia> @with_kw struct Foo
             x=1
             y=2
             end                                                                                                                                             
FFoo                                                                                                                                                         

julia> Foo(Foo())                                                                                                                                            
Foo                                                                                                                                                          
  x: Int64 1                                                                                                                                                 
  y: Int64 2                                                                                                                                                 

You have these ShiftedArrays showing up in your stack trace. What are those?

[cstjean]

Good catch, it only happens with ShiftedArrays imported. Looks like type piracy.

julia> using Parameters, ShiftedArrays

julia> @with_kw struct Foo
       x=1
       y=2
       end
Foo

julia> Foo(Foo())
ERROR: StackOverflowError:
Stacktrace:
 [1] Base.Generator(::getfield(ShiftedArrays, Symbol("##35#36")){Tuple{}}, ::Array{Union{},1}) at ./generator.jl:32
 [2] convert(::Type{Array{Union{},1}}, ::Array{Union{},1}) at /home/cst-jean/.julia/packages/ShiftedArrays/psVhR/src/offset.jl:2

[cstjean]

cc @piever

[piever]

Ups, that's bad! I'll make the package type-piracy free and tag a new release soon

[piever]

ShiftedArrays "only" pirates AbstractArray{<: ShiftedArray} so I'm still not sure how that creates this bug

[cstjean]

That's not even type-piracy. Hmm. I'll check tomorrow which version I'm using, I can't seem to reproduce it at home.

[cstjean]

At work, I'm definitely hitting it with the code above using ShiftedArrays. Maybe it's something else that's peculiar to my setup? Can anyone else reproduce? I'm on 0.7, [d96e819e] Parameters v0.9.2; [1277b4bf] ShiftedArrays v0.3.3

[piever]

I think I see what it is now. It's definitely unexpected and a consequence of my piracy:

julia> Array{Union{}} <: AbstractArray{<:ShiftedArray}
true

Somehow for Parameters it's important to convert a Array{Union{}} to Array and I'm pirating that method.

For the time being you can probably just comment out the incriminated method and I'll fix ShiftedArrays.

[cstjean]

JuliaLang/julia#28798

[cstjean]

@piever I hit this again today with another of your packages.

julia> using ShiftedArrays, InteractBase

julia> InteractBase.textbox()
ERROR: StackOverflowError:
Stacktrace:
 [1] Base.Generator(::getfield(ShiftedArrays, Symbol("##35#36")){Tuple{}}, ::Array{Union{},1}) at ./generator.jl:32
 [2] convert(::Type{Array{Union{},1}}, ::Array{Union{},1}) at /home/cst-jean/.julia/packages/ShiftedArrays/psVhR/src/offset.jl:2
 ... (the last 2 lines are repeated 26665 more times)
 [53333] Base.Generator{Array{Union{},1},getfield(ShiftedArrays, Symbol("##35#36")){Tuple{}}}(::Function, ::Array{Union{},1}) at ./generator.jl:32 (repeats 2 times)

[cstjean]

But I really do feel like your code is legit. Base should not be converting to Array{Union{}} IMHO

[piever]

Thanks for reporting, I too had noticed some issues with InteractBase. As a practical solution, unless there is a confirmation soonish in the other issue that it'll be fixed on the side of Base, I'll remove my convert overload.