Elasticsearch-net: SIGSEGV when indexing nullable value tuple with value

[leo-labs]

NEST/Elasticsearch.Net version:
7.6.1/7.7

Elasticsearch version:
7.6.2

Runtime/OS info
dotnet 3.1.201 on Mac OS X 10.14.4 (BuildVersion: 18E226)

Description of the problem including expected versus actual behavior:

Indexing a document that contains a property that is a nullable value tuple such as (string info, int number)? with a value that is not null produces a SIGSEGV and the whole application crashes.

Steps to reproduce:

The issue can be reproduced with the following code:

using System;
using Nest;

public class ExampleDoc {
    public (string info, int number)? tupleNullable { get; set; }
}

public class Program {
    public static void Main() {
        var node = new Uri("http://localhost:9200");
        var client = new ElasticClient(new ConnectionSettings(node));

        var doc = new ExampleDoc {
            tupleNullable = ("somestring", 42),
        };

                var indexName= "index4";
                client.Indices.Create(indexName, index => index
                        .Map<ExampleDoc>(m => m
                        .AutoMap()
                ));

               client.Index(doc, i => i.Index(indexName));
    }
}

Expected behavior
The expected bahavior is to either throw an exception if this usecase is not supported or to successfully index the document

[russcam]

Thanks for reporting @leo-labs. Looks like ValueTuple? needs special handling to be supported. On Windows, it looks like it enters into an infinite loop.

[russcam]

Stack trace on netcoreapp3.1 on Windows

Fatal error. Internal CLR error. (0x80131506)
   at System.Runtime.CompilerServices.ITuple.get_Length()
   at DynamicClass.Serialize(Byte[][], System.Object[], Elasticsearch.Net.Utf8Json.JsonWriter ByRef, System.ValueTuple`2<System.String,Int32>, Elasticsearch.Net.Utf8Json.IJsonFormatterResolver)
   at Elasticsearch.Net.Utf8Json.Resolvers.DynamicMethodAnonymousFormatter`1[[System.ValueTuple`2[[System.__Canon, System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e],[System.Int32, System.
Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]], System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]].Serialize(Elasticsearch.Net.Utf8Json.JsonWriter By
Ref, System.ValueTuple`2<System.__Canon,Int32>, Elasticsearch.Net.Utf8Json.IJsonFormatterResolver)
   at Elasticsearch.Net.Utf8Json.Formatters.StaticNullableFormatter`1[[System.ValueTuple`2[[System.__Canon, System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e],[System.Int32, System.Private
.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]], System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]].Serialize(Elasticsearch.Net.Utf8Json.JsonWriter ByRef, Sy
stem.Nullable`1<System.ValueTuple`2<System.__Canon,Int32>>, Elasticsearch.Net.Utf8Json.IJsonFormatterResolver)
   at DynamicClass.Serialize(Byte[][], System.Object[], Elasticsearch.Net.Utf8Json.JsonWriter ByRef, GitHubIssue4703.ExampleDoc, Elasticsearch.Net.Utf8Json.IJsonFormatterResolver)
   at Elasticsearch.Net.Utf8Json.Resolvers.DynamicMethodAnonymousFormatter`1[[System.__Canon, System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]].Serialize(Elasticsearch.Net.Utf8Json.JsonW
riter ByRef, System.__Canon, Elasticsearch.Net.Utf8Json.IJsonFormatterResolver)
   at Elasticsearch.Net.Utf8Json.JsonSerializer.SerializeUnsafe[[System.__Canon, System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]](System.__Canon, Elasticsearch.Net.Utf8Json.IJsonFormatt
erResolver)
   at Elasticsearch.Net.Utf8Json.JsonSerializer.Serialize[[System.__Canon, System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]](System.IO.Stream, System.__Canon, Elasticsearch.Net.Utf8Json.
IJsonFormatterResolver)
   at Nest.DefaultHighLevelSerializer.Serialize[[System.__Canon, System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]](System.__Canon, System.IO.Stream, Elasticsearch.Net.SerializationFormat
ting)
   at Elasticsearch.Net.DiagnosticsSerializerProxy.Serialize[[System.__Canon, System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]](System.__Canon, System.IO.Stream, Elasticsearch.Net.Serial
izationFormatting)
   at Nest.IndexDescriptor`1[[System.__Canon, System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]].Nest.IProxyRequest.WriteJson(Elasticsearch.Net.IElasticsearchSerializer, System.IO.Stream,
 Elasticsearch.Net.SerializationFormatting)
   at Nest.ProxyRequestFormatterBase`2[[System.__Canon, System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e],[System.__Canon, System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, Public
KeyToken=7cec85d7bea7798e]].Serialize(Elasticsearch.Net.Utf8Json.JsonWriter ByRef, System.__Canon, Elasticsearch.Net.Utf8Json.IJsonFormatterResolver)
   at Elasticsearch.Net.Utf8Json.JsonSerializer.SerializeUnsafe[[System.__Canon, System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]](System.__Canon, Elasticsearch.Net.Utf8Json.IJsonFormatt
erResolver)
   at Elasticsearch.Net.Utf8Json.JsonSerializer.Serialize[[System.__Canon, System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]](System.IO.Stream, System.__Canon, Elasticsearch.Net.Utf8Json.
IJsonFormatterResolver)
   at Nest.DefaultHighLevelSerializer.Serialize[[System.__Canon, System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]](System.__Canon, System.IO.Stream, Elasticsearch.Net.SerializationFormat
ting)
   at Elasticsearch.Net.DiagnosticsSerializerProxy.Serialize[[System.__Canon, System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]](System.__Canon, System.IO.Stream, Elasticsearch.Net.Serial
izationFormatting)
   at Elasticsearch.Net.SerializableData`1[[System.__Canon, System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]].Write(System.IO.Stream, Elasticsearch.Net.IConnectionConfigurationValues)
   at Elasticsearch.Net.InMemoryConnection.ReturnConnectionStatus[[System.__Canon, System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]](Elasticsearch.Net.RequestData, Byte[], System.Nullabl
e`1<Int32>, System.String)
   at Elasticsearch.Net.InMemoryConnection.Request[[System.__Canon, System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]](Elasticsearch.Net.RequestData)
   at Elasticsearch.Net.RequestPipeline.CallElasticsearch[[System.__Canon, System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]](Elasticsearch.Net.RequestData)
   at Elasticsearch.Net.Transport`1[[System.__Canon, System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]].Request[[System.__Canon, System.Private.CoreLib, Version=4.0.0.0, Culture=neutral,
PublicKeyToken=7cec85d7bea7798e]](Elasticsearch.Net.HttpMethod, System.String, Elasticsearch.Net.PostData, Elasticsearch.Net.IRequestParameters)
   at Elasticsearch.Net.ElasticLowLevelClient.DoRequest[[System.__Canon, System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]](Elasticsearch.Net.HttpMethod, System.String, Elasticsearch.Net.
PostData, Elasticsearch.Net.IRequestParameters)
   at Nest.ElasticClient.DoRequest[[System.__Canon, System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e],[System.__Canon, System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyT
oken=7cec85d7bea7798e]](System.__Canon, Elasticsearch.Net.IRequestParameters, System.Action`1<Elasticsearch.Net.IRequestConfiguration>)
   at Nest.ElasticClient.Index[[System.__Canon, System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]](Nest.IIndexRequest`1<System.__Canon>)
   at Nest.ElasticClient.Index[[System.__Canon, System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]](System.__Canon, System.Func`2<Nest.IndexDescriptor`1<System.__Canon>,Nest.IIndexRequest`
1<System.__Canon>>)
   at GitHubIssue4703.Program.Main(System.String[])

[russcam]

I've added a test branch, fix/4703 with a unit test to reproduce, https://github.com/elastic/elasticsearch-net/commit/61386f307f0eac5f1c6985ec245abb76b28e73e7. The unit test passes when run as part of the unit test suite e.g.

./build skipdocs

Will need to dig further.

[leo-labs]

Thanks for investigating!

On a different note, I would like to point out that the behavior with named value tuples is counterintuitive: If I have (string status, int code) myTuple auto-mapping does not preserve the item names but substitutes status with item1 and code with item2.

[russcam]

On a different note, I would like to point out that the behavior with named value tuples is counterintuitive: If I have (string status, int code) myTuple auto-mapping does not preserve the item names but substitutes status with item1 and code with item2.

The semantic names are syntactical sugar that Roslyn can understand, but ultimately, the IL generates Item* fields for ValueTuple<>. As an example

```c#
void Main()
{
var example = new ExampleDoc
{
tupleNullable = ("somestring", 42)
};

var info = example.tupleNullable.Value.info;

}

public class ExampleDoc
{
public (string info, int number)? tupleNullable { get; set; }
}

generates the following IL

IL_0000: nop
IL_0001: newobj UserQuery+ExampleDoc..ctor
IL_0006: dup
IL_0007: ldstr "somestring"
IL_000C: ldc.i4.s 2A
IL_000E: newobj System.ValueTuple..ctor
IL_0013: newobj System.Nullable>..ctor
IL_0018: callvirt UserQuery+ExampleDoc.set_tupleNullable
IL_001D: nop
IL_001E: stloc.0
IL_001F: ldloc.0
IL_0020: callvirt UserQuery+ExampleDoc.get_tupleNullable
IL_0025: stloc.2
IL_0026: ldloca.s 02
IL_0028: call System.Nullable>.get_Value
IL_002D: ldfld System.ValueTuple.Item1
IL_0032: stloc.1
IL_0033: ret
```

You can see that assigning the value of example.tupleNullable.Value.info to the variable info generates ldfld System.ValueTuple<System.String,System.Int32>.Item1. If names are important in the emitted JSON, I would suggest using properties on the POCO instead.

[russcam]

This is now fixed and nullable ValueTuples supported in 7.7.1

[xsoheilalizadeh]

I'm facing this in ElasticSearch.Net 7.7.1, seems It's not able to serialize StringValues

[russcam]

@xsoheilalizadeh StringValues are not currently supported. It might be best to open a new issue for this to discuss 👍

[xsoheilalizadeh]

@russcam, I'm already working on implementing its formatter, will make the issue for that.