Fixed #12079: Changed has_results to get a single result, thus preventing exists() from always returning True on backends that support chunked reads.
Fixed #12079: Changed has_results to get a single result, thus preventing exists() from always returning True on backends that support chunked reads.

--HG--
extra : convert_revision : svn%3Abcc190cf-cafb-0310-a4f2-bffc1f526a37/django/trunk%4011654

adieu/django-nonrel,adieu/django-nonrel,adieu/django-nonrel