SQL: querying an alias having different mappings indices generates an incorrect error message

[astefan]

For an alias defined as

$ curl -XGET "localhost:9200/_alias/test_alias?pretty"
{
  "test_emp_copy" : {
    "aliases" : {
      "test_alias" : { }
    }
  },
  "library" : {
    "aliases" : {
      "test_alias" : { }
    }
  },
  "test_emp" : {
    "aliases" : {
      "test_alias" : { }
    }
  }
}

the error message received is:

sql> select * from test_alias;
Bad request [Found 1 problem(s)
line 1:15: [test_alias] points to indices [library] and [library] which have different mappings. When using multiple indices, the mappings must be identical.]

(twice the library index mentioned instead of library and another index from the alias)
Those three indices mappings are like this:

• test_emp_copy and test_emp are identical
• library is completely different from the other two

[elasticmachine]

Pinging @elastic/es-search-aggs

[costin]

Looks like a duplicate of #31611

[costin]

Fixed by #31792