Avoids joining with the wrong tables when connecting select_related() tables to
the main query. This also leads to slightly more efficient (meaning less tables
are joined) SQL queries in some other cases, too. Some unnecessary tables are
now trimmed that were not previously.
git-svn-id: http://code.djangoproject.com/svn/django/trunk@7741 bcc190cf-cafb-0310-a4f2-bffc1f526a37
Previously, if we were querying across a nullable join and then a non-nullable
one, the second join would not be a LEFT OUTER join, which would exclude
certain valid results from the result set.
This is the same problem as [7597] but for values() field specifications, so
this covers the second case where Django adds extra stuff to the select-clause.
git-svn-id: http://code.djangoproject.com/svn/django/trunk@7740 bcc190cf-cafb-0310-a4f2-bffc1f526a37