Incorrect function behaviour when language is not specified

[tzdybal]

mutation {
  schema {
    test: string @index(hash, term) .
  }
  set {
    <_:t1> <test> "India"@en .
  }
}

Query:

{
  i(func:eq(test, "India")) {
    tae: test@en
    ta: test
  }
}

Query returns no results, but according to docs it should.

Note In functions, language lists and . notation are not allowed. In functions, a string edge without a language tag means apply function to all languages, while a single language tag means apply to only the given language.

[tzdybal]

Problem is visible only for hash index. With exact index eq works as expected.

[tzdybal]

Seems that problem is visible for all functions and index types. Previous tests were to trivial - English was the only language used, therefore it was selected as 'any language'.

[manishrjain]

This is how we currently do retrieval:

Retrieval:
test@en => English
test@. => Any language
test => Value without lang tag

We should implement the function in the same manner.