Calling the "repr" function on an object which both auto-reference itself and inherits from "Function" cause a StackOverflowError

[AFatNiBBa]

struct a <: Function
	x::Dict
end

The struct "a" inherit from the abstract type "Function" and contains a "Dict"

b = a(Dict{Any, Any}(1 => 1, 2 => 2, 3 => 3))
#output:
# (::a) (generic function with 0 methods)

b.x[2] = b
#output:
# (::a) (generic function with 0 methods)

The struct gets instantiated and an element of the field "x" is assigned with the instance itself

repr(b)
#output:
# ERROR: StackOverflowError:
# Stacktrace:
#  [1] _show_default(::Base.GenericIOBuffer{Array{UInt8,1}}, ::Any) at .\show.jl:396
#  [2] show_default at .\show.jl:389 [inlined]
#  [3] show_function(::Base.GenericIOBuffer{Array{UInt8,1}}, ::Function, ::Bool) at .\show.jl:445
#  [4] print(::Base.GenericIOBuffer{Array{UInt8,1}}, ::Function) at .\show.jl:461
#  [5] print_to_string(::Function) at .\strings\io.jl:135
#  [6] string at .\strings\io.jl:174 [inlined]
#  [7] Symbol at .\strings\basic.jl:227 [inlined]
#  [8] isdelimited(::IOContext{Base.GenericIOBuffer{Array{UInt8,1}}}, ::Function) at .\show.jl:664
#  [9] show(::IOContext{Base.GenericIOBuffer{Array{UInt8,1}}}, ::Pair{Any,Any}) at .\show.jl:682
#  [10] show(::IOContext{Base.GenericIOBuffer{Array{UInt8,1}}}, ::Dict{Any,Any}) at .\dict.jl:38
#  [11] _show_default(::Base.GenericIOBuffer{Array{UInt8,1}}, ::Any) at .\show.jl:406
#  ... (the last 10 lines are repeated 5022 more times)
#  [50232] show_default at .\show.jl:389 [inlined]
#  [50233] show_function(::Base.GenericIOBuffer{Array{UInt8,1}}, ::Function, ::Bool) at .\show.jl:445
#  [50234] show(::Base.GenericIOBuffer{Array{UInt8,1}}, ::Function) at .\show.jl:460
#  [50235] sprint(::Function, ::Function; context::Nothing, sizehint::Int64) at .\strings\io.jl:105
#  [50236] #repr#356 at .\strings\io.jl:227 [inlined]
#  [50237] repr(::Function) at .\strings\io.jl:227

When calling the "repr" function on the object it gives a StackOverflowError, but it is not normal since the function can handle circular references.
I don't think I'm the one that made the mistake because executing the same code but with"a" not being a subtype of "Function" goes as expected:

struct a
	x::Dict
end

b = a(Dict{Any, Any}(1 => 1, 2 => 2, 3 => 3))
#output:
# (::a) (generic function with 0 methods)

b.x[2] = b
#output:
# (::a) (generic function with 0 methods)

repr(b)
#output:
# "a(Dict{Any,Any}(2 => a(#= circular reference @-2 =#),3 => 3,1 => 1))"

#=
Julia Version 1.5.1
Commit 697e782ab8 (2020-08-25 20:08 UTC)
Platform Info:
  OS: Windows (x86_64-w64-mingw32)
  CPU: AMD Ryzen 5 3600 6-Core Processor
  WORD_SIZE: 64
  LIBM: libopenlibm
  LLVM: libLLVM-9.0.1 (ORCJIT, znver2)
=#