Elasticsearch-net: position overflowed when bulk index and phrases

[MartinDemberger]

NEST/Elasticsearch.Net version: 7.11.1

Elasticsearch version: 7.11.1

Description of the problem including expected versus actual behavior:
I have an index with a text field with IndexPhrases enabled. The entity has a List property. When I index a document with the values "bad", "Prio 1" I get an error which wasn't there in the 7.10 version.

Steps to reproduce:

Execute the following unit test

using System;
using System.Collections.Generic;
using System.Threading.Tasks;
using Elasticsearch.Net;
using Nest;
using Xunit;

namespace ElasticError
{
    public class MyTest
    {
        [Fact]
        public async Task TestRaw()
        {
            var indexName = $"{ Guid.NewGuid()}";

            var connectionPool = new SingleNodeConnectionPool(new Uri("http://localhost:9200"));

            var connectionSettings = new ConnectionSettings(connectionPool)
                .DefaultMappingFor<ElasticTestIndexEntry>(m => m
                    .IndexName(indexName)
                )
                .EnableDebugMode()
                .DisableDirectStreaming();

            var client = new ElasticClient(connectionSettings);


            try
            {
                var entry = new ElasticTestIndexEntry()
                {
                    Tags = new List<string>() {
                        "bad",
                        "Prio 1"
                    },
                };


                await client.Indices.CreateAsync(indexName, c => c
                .Map<ElasticTestIndexEntry>(s => s
                    .AutoMap()
                    .Properties(p => p
                            .Text(t => t
                                .Name(e => e.Tags)
                                .IndexPhrases()
                            )
                        )
                    )
                );

                var bulkEntry = new BulkDescriptor();
                bulkEntry.Refresh(Refresh.True);
                bulkEntry.Index<ElasticTestIndexEntry>(i => i.Document(entry));
                var bulkResponse = await client.BulkAsync(bulkEntry);
                if (bulkResponse.Errors)
                    throw new Exception(bulkResponse.DebugInformation);
            }
            finally
            {
                await client.Indices.DeleteAsync(indexName);
            }
        }

        public class ElasticTestIndexEntry
        {
            public List<string> Tags { get; set; }
        }
    }
}

Expected behavior
The document is created without an error.

Provide ConnectionSettings (if relevant):

Provide DebugInformation (if relevant):

 ElasticError.MyTest.TestRaw
   Source: TestIndexTest.cs line 13
   Duration: 1 sec

  Message: 
    System.Exception : Invalid NEST response built from a successful (200) low level call on POST: /_bulk?pretty=true&error_trace=true&refresh=true
    # Invalid Bulk items:
      operation[0]: index returned 400 _index: cb100c98-0899-4841-ab37-f1237799142e _type: _doc _id: mVr6_ncBR5uDxQ8nh-cX _version: 0 error: Type: illegal_argument_exception Reason: "position overflowed Integer.MAX_VALUE (got posIncr=1 lastPosition=0 position=-1) for field 'tags._index_phrase'"
    # Audit trail of this API call:
     - [1] HealthyResponse: Node: http://localhost:9200/ Took: 00:00:00.1895416
    # Request:
    {"index":{"_id":null,"_index":"cb100c98-0899-4841-ab37-f1237799142e"}}
    {"tags":["bad","Prio 1"]}

    # Response:
    {
      "took" : 133,
      "errors" : true,
      "items" : [
        {
          "index" : {
            "_index" : "cb100c98-0899-4841-ab37-f1237799142e",
            "_type" : "_doc",
            "_id" : "mVr6_ncBR5uDxQ8nh-cX",
            "status" : 400,
            "error" : {
              "type" : "illegal_argument_exception",
              "reason" : "position overflowed Integer.MAX_VALUE (got posIncr=1 lastPosition=0 position=-1) for field 'tags._index_phrase'"
            }
          }
        }
      ]
    }

    # TCP states:
      TimeWait: 9
      Established: 61

    # ThreadPool statistics:
      Worker: 
        Busy: 2
        Free: 32765
        Min: 8
        Max: 32767
      IOCP: 
        Busy: 0
        Free: 1000
        Min: 8
        Max: 1000

[stevejgordon]

Thanks for the detailed repro @MartinDemberger. I don't believe we consciously changed anything which should have changed the client behaviour around this between 7.1 and 7.11. I'll pick this up next week to investigate further.

[stevejgordon]

Thanks again for reporting this @MartinDemberger. After reviewing it this morning, it appears to be a bug on the server so I've raised an issue for it to be tracked and addressed there. I'll close this issue as I don't believe this requires any client changes.