Wrong result of "simple_query_search" with prefix query.

[lbrzekowski]

Elasticsearch version
6.1.0

Plugins installed: []

JVM version (java -version):
java version "1.8.0_131"
Java(TM) SE Runtime Environment (build 1.8.0_131-b11)
Java HotSpot(TM) 64-Bit Server VM (build 25.131-b11, mixed mode)

OS version:
Ubuntu 17.10 with 4.13.0-21-generic

Description of the problem including expected versus actual behavior:
When index's mapping includes text and date properties, result of simple_query_search, which includes asterisk for prefix query,
returns no documents.
When there's no date properties on index's mappping, query works fine.
The same query works fine on 5.6 version.

Steps to reproduce:

1. Create index "tests" with text and date properties.

curl -XPUT http://localhost:9200/tests -H 'Content-Type: application/json' -H 'Accept: application/json' -d '{
  "mappings": {
    "test": {
      "properties": {
        "date": {
          "type": "date"
        },
        "name": {
          "type": "text",
          "fields": {
            "raw": {
              "type": "keyword"
            }
          }
        }
      }
    }
  }
}'

2. Put some data

curl -XPUT http://localhost:9200/tests/test/1 -H 'Content-Type: application/json' -H 'Accept: application/json' -d '
{
  "date": "2018-01-12",
  "name": "test1"
}'

3. Try to search with simple_query_search and asterisk.

curl -XPOST http://localhost:9200/tests/_search -H 'Content-Type: application/json' -H 'Accept: application/json' -d '
{
  "query": {
    "simple_query_string": {
      "query": "te*"
    }
  }
}'

Received result: no documents found
Expected result: document with id 1 found

Provide logs (if relevant):
there's no errors on logs

[dakrone]

I was able to reproduce this on ES 6.1.0 and 6.1.1, for some reason it's being rewritten to "explanation" : "MatchNoDocsQuery(\"empty string passed to query parser\")"

For the meantime, query_string behaves correctly and retrieves the document.

[lbrzekowski]

@jimczi I've built elasticsearch from your branch 'bugs/lenient_simple_query_string' and I run steps to reproduce the bug and nothing changes from my perspective. The response is still 0 documents instead of 1 document found. I've noticed that the only change is in "explanation.description" in response of

curl -XPOST http://localhost:9200/tests/test/1/_explain -H 'Content-Type: application/json' -H 'Accept: application/json' -d '
{
  "query": {
    "simple_query_string": {
      "query": "te*"
    }
  }
}'

[jimczi]

You're right @lbrzekowski, my fix was only to get the expected exceptions. I pushed another commit to continue with the other fields when leniency is on and we hit an exception on a field.