Null reference exception in Escaping.escape

[haf]

  System.NullReferenceException: Object reference not set to an instance of an object
  at Chiron+Escaping+escape@401-1.GenerateNext (System.Collections.Generic.IEnumerable`1[System.Char]& next) [0x00028] in Chiron.fs:401
  at Microsoft.FSharp.Core.CompilerServices.GeneratedSequenceBase`1[T].MoveNextImpl () [0x00017] in /private/tmp/mono--fsharp-20170301-46369-1vnanly/src/fsharp/FSharp.Core/seq.fs:781
  at Microsoft.FSharp.Core.CompilerServices.GeneratedSequenceBase`1[T].System-Collections-IEnumerator-MoveNext () [0x00000] in /private/tmp/mono--fsharp-20170301-46369-1vnanly/src/fsharp/FSharp.Core/seq.fs:812
  at Microsoft.FSharp.Collections.SeqModule.ToList[T] (System.Collections.Generic.IEnumerable`1[T] source) [0x00000] in /private/tmp/mono--fsharp-20170301-46369-1vnanly/src/fsharp/FSharp.Core/seq.fs:559
  at Chiron+Escaping.escape (System.String s) [0x00010] in <58e26eef7a9f4a1fa7450383ef6ee258>:0
  at Chiron+Formatting.formatString (System.String _arg7) [0x00000] in Chiron.fs:692
  at Chiron+Formatting.formatJson (System.Int32 level, Chiron+Formatting+JsonFormattingOptions options, Chiron+Json _arg1) [0x00082] in Chiron.fs:661

For the last release, unknown tag.

Repro:

Object (Map [("key", String null)]) |> Json.serialize

[neoeinstein]

The internal type escape@401-1 exists in Chiron 6.2.0. Upgrading to 6.2.1 should solve this issue along with #64.

[haf]

Testing...

[haf]

No, I'm already using Chiron 6.2.1

[neoeinstein]

Then the stack trace is suspect. escape@401-1 does not exist in Chiron 6.2.1.

[haf]

Well, that's because there are no tags on this repo and I took an arbitrary commit to get some sort of debug symbols... :-s

[haf]

Does the repro fail for you?

[haf]

I just tried pdb2mdb with this result:

$ pdb2mdb packages/Chiron/lib/net40/Chiron.dll
$ xbuild /t:Rebuild ... fsproj && mono --debug ...exe
Symbol file Tests/bin/Debug/Chiron.dll.mdb doesn't match image Tests/bin/Debug/Chiron.dll

I also tried to verify the version of Chiron, but there's none in the DLL:

$ monodis --assembly Tests/bin/Debug/Chiron.dll | grep VERSION
$

[neoeinstein]

On Windows, I have no issues with a build from clean. I'll have to see if I can get a mono build going this evening.

[haf]

Did you see it? :)

[laygr]

As a little hack, I wrote this:

type Json with
    static member writeCaringForNull (key: string) value =
        json {
            if isNull value
            then do! Json.writeNone key
            else do! Json.write key value
        }

then, you can do this:

json {
     do! Json.writeCaringForNull aKey aValue
}