HStore values query with contains not working as expected

[Alex Magidow]

Hi,

I was going to file this as a bug, but it said to ask the mailing list first.

When using an HStore __values query with __contains chained on to it, the query does not work as expected in Django 1.8.2. Expected action is that any values which contain the text will be returned from the query.

From my own app (I've removed some of the queryset results to make this easier to read)

>>> query1
[<LanguageDatum: \xf0i, This (m), And, >, <LanguageDatum: hadi, This (f), AfgA, >, <LanguageDatum: -e, His, ArBah, >, '...(remaining elements truncated)...']
>>> query1.filter(multigloss__values__contains=["This"])
[]
>>> query1.filter(multigloss__values__contains=["This (f)"])
[<LanguageDatum: hadi, This (f), AfgA, >,  <LanguageDatum: \xf0i, This (f), ArAnz, >, '...(remaining elements truncated)...']
>>> query1.filter(multigloss__values__contains=["His"])
[<LanguageDatum: -e, His, ArBah, >, <LanguageDatum: -eh, His, ArBah, >, <LanguageDatum: -hu, His, Chd, >, <LanguageDatum: -u, His, Chd, > '...(remaining elements truncated)...']
>>> query1.filter(multigloss__values__contains=["Hi"])
[]

The expected result would be that the queries would return any data whose 'multigloss' values contain the string, not only those strings which are exactly identical.

The example in the documentation should also fail if you did not include the entire word "collie" (I have not tested, this is a hypothesized result):

>>> Dog.objects.create(name='Rufus', data={'breed': 'labrador'})
>>> Dog.objects.create(name='Meg', data={'breed': 'collie', 'owner': 'Bob'})

>>> Dog.objects.filter(data__values__contains=['collie'])
[<Dog: Meg>]

>>>#Hypothesized example!
>>> Dog.objects.filter(data__values__contains=['coll'])
[]
>>>#Should have returned [Dog: Meg]

Is there a way to do the query that I'm trying to do here, or have I found a bug?

Thanks,
Alex