Fixed #20348 -- Consistently handle Promise objects in model fields.

All Promise objects were passed to force_text() deep in ORM query code.
Not only does this make it difficult or impossible for developers to
prevent or alter this behaviour, but it is also wrong for non-text
fields.

This commit changes `Field.get_prep_value()` from a no-op to one that
resolved Promise objects. All subclasses now call super() method first
to ensure that they have a real value to work with.

1 files changed, 0 insertions, 12 deletions

diff --git a/django/db/models/sql/subqueries.py b/django/db/models/sql/subqueries.py
index 6aab02bd9a..8beb3fa74a 100644
--- a/django/db/models/sql/subqueries.py
+++ b/django/db/models/sql/subqueries.py
@@ -11,8 +11,6 @@ from django.db.models.sql.constants import GET_ITERATOR_CHUNK_SIZE, SelectInfo
 from django.db.models.sql.datastructures import Date, DateTime
 from django.db.models.sql.query import Query
 from django.db.models.sql.where import AND, Constraint
-from django.utils.functional import Promise
-from django.utils.encoding import force_text
 from django.utils import six
 from django.utils import timezone
 
@@ -147,10 +145,6 @@ class UpdateQuery(Query):
         Used by add_update_values() as well as the "fast" update path when
         saving models.
         """
-        # Check that no Promise object passes to the query. Refs #10498.
-        values_seq = [(value[0], value[1], force_text(value[2]))
-                      if isinstance(value[2], Promise) else value
-                      for value in values_seq]
         self.values.extend(values_seq)
 
     def add_related_update(self, model, field, value):
@@ -210,12 +204,6 @@ class InsertQuery(Query):
         into the query, for example.
         """
         self.fields = fields
-        # Check that no Promise object reaches the DB. Refs #10498.
-        for field in fields:
-            for obj in objs:
-                value = getattr(obj, field.attname)
-                if isinstance(value, Promise):
-                    setattr(obj, field.attname, force_text(value))
         self.objs = objs
         self.raw = raw