search_after is not support geo_distance

[ztianyi312]

Describe the feature:
We want to use search_after when sorting by geo_distance

[jimczi]

This is already supported:

PUT t
{
  "mappings": {
    "doc": {
      "properties": {
        "location": {
          "type": "geo_point"
        }
      }
    }
  }
}

PUT t/doc/1
{
  "location": [-75, 40]
}

PUT t/doc/2
{
  "location": [-75, 40]
}

# returns only doc 2
GET t/_search
{
    "sort" : [
        {
            "_geo_distance" : {
                "location" : [-70, 40],
                "order" : "asc",
                "unit" : "km",
                "mode" : "min",
                "distance_type" : "arc"
            }
        }
    ],
    "search_after": [0]
}

[vseryakov]

Gives an error: Comparator type [CUSTOM] for field [latlon] is not supported in 5.5 and 5.6,

the query is:

{ query: { bool: { must: { query_string: { query: '(status:Ready)' } }, filter: { geo_distance: { distance: 5000, latlon: [ 150.98081635595673, -34.194085878589426 ] } } } }, sort: [ { _geo_distance: { latlon: [ 150.98081635595673, -34.194085878589426 ], order: 'asc', unit: 'm', distance_type: 'arc' } } ], size: 3, search_after: [0] }

the latlon field is type of geo_point

[jimczi]

search_after fails when you set unit to m due to an internal optimization. Sorry I missed this case and thanks @vseryakov for spotting !
I opened #26891