Fix Vararg separately

src/anonymous.jl

@@ -60,6 +60,8 @@ function newstruct!(meth::Method, mod, name, file, line, sig,
 end
 end
 
+# Type Names
+
 if VERSION < v"1.7-"
 function structdata(t::TypeName)
   primary = Base.unwrap_unionall(t.wrapper)
@@ -83,7 +85,10 @@ function structdata(t::TypeName)
 end
 end
 
-# Type Names
+if VERSION >= v"1.7-"
+structdata(x::Core.TypeofVararg) =
+  Any[getfield(x, f) for f in fieldnames(typeof(x)) if isdefined(x, f)]
+end
 
 baremodule __deserialized_types__ end
 

test/runtests.jl

@@ -101,6 +101,26 @@ end
   @test x.x === x
 end
 
+@testset "Undefined References" begin
+  # from Issue #3
+  d = Dict(:a => 1, :b => Dict(:c => 3, :d => Dict("e" => 5)))
+  @test roundtrip_equal(d)
+
+  # from Issue #43
+  x = Array{String, 1}(undef, 5)
+  x[1] = "a"
+  x[4] = "d"
+  @test_broken roundtrip_equal(Dict(:x => x))
+
+  struct NoInit
+    x::Int
+
+    NoInit() = new()
+  end
+  x = NoInit()
+  @test roundtrip_equal(x)
+end
+
 @testset "Anonymous Functions" begin
   f = x -> x+1
   if VERSION < v"1.7-"