FieldStatistics.cs class has int values but can get from indexes long values

[guille11gg]

NEST/Elasticsearch.Net version: 7.6.1

Elasticsearch version: 6.8

Description of the problem including expected versus actual behavior:
A clear and concise description of what the bug is.
This class is getting integers in all their properties: https://github.com/elastic/elasticsearch-net/blob/master/src/Nest/Document/Single/TermVectors/FieldStatistics.cs
Can be the case, when you do a termVectors query, those number are bigger than an integer (long).

Steps to reproduce:

1. Query to termVectors: POST https://host/index/_mtermvectors
2. An exception is triggered: "Unhandled exception when processing list: efefdb47-0aaf-4244-9c96-7e971cba3c46. - Elasticsearch.Net.UnexpectedElasticsearchClientException: JSON integer 2320738168 is too large or small for an Int32. Path 'docs[0].term_vectors.abstractFull.field_statistics.sum_ttf'

Expected behavior
Be able to map all properties.

Provide ConnectionSettings (if relevant):

Provide DebugInformation (if relevant):

[russcam]

Thanks for opening @guille11gg.

Looking at FieldStatistics in Elasticsearch source, SumOfDocumentFrequencies and SumOfTotalTermFrequencies should be long.

Changing these to long in 7.x would technically be a breaking change. I see a couple of options:

1. Accept the breaking change in a minor version, as impact in doing so is likely low. For clarity, the semantic versioning of the library is bound to the versioning of Elasticsearch.
2. Introduce SumOfDocumentFrequenciesLong and SumOfTotalTermFrequenciesLong long type properties to deserialize to, with existing int properties returning these values.

[codebrain]

Technically a breaking change, but I suspect moving from int to long in this case should be of limited impact. My vote for 1.

[russcam]

I'm +1 on changing them to long too

[guille11gg]

Hi all,

Will the fix of this bug release in v.7.7.0?

What´s the date expected of that release?

thanks a lot.