Fixed #24104 -- Fixed check to look on field.many_to_many instead of class instance

2 files changed, 6 insertions, 8 deletions

diff --git a/django/db/backends/base/schema.py b/django/db/backends/base/schema.py
index 09db3f1096..8ec92ebf6a 100644
--- a/django/db/backends/base/schema.py
+++ b/django/db/backends/base/schema.py
@@ -1,7 +1,6 @@
 import hashlib
 
 from django.db.backends.utils import truncate_name
-from django.db.models.fields.related import ManyToManyField
 from django.db.transaction import atomic
 from django.utils import six
 from django.utils.encoding import force_bytes
@@ -380,7 +379,7 @@ class BaseDatabaseSchemaEditor(object):
         table instead (for M2M fields)
         """
         # Special-case implicit M2M tables
-        if isinstance(field, ManyToManyField) and field.rel.through._meta.auto_created:
+        if field.many_to_many and field.rel.through._meta.auto_created:
             return self.create_model(field.rel.through)
         # Get the column's definition
         definition, params = self.column_sql(model, field, include_default=True)
@@ -424,7 +423,7 @@ class BaseDatabaseSchemaEditor(object):
         but for M2Ms may involve deleting a table.
         """
         # Special-case implicit M2M tables
-        if isinstance(field, ManyToManyField) and field.rel.through._meta.auto_created:
+        if field.many_to_many and field.rel.through._meta.auto_created:
             return self.delete_model(field.rel.through)
         # It might not actually have a column behind it
         if field.db_parameters(connection=self.connection)['type'] is None:
diff --git a/django/db/backends/sqlite3/schema.py b/django/db/backends/sqlite3/schema.py
index 814b94ffee..031bf77840 100644
--- a/django/db/backends/sqlite3/schema.py
+++ b/django/db/backends/sqlite3/schema.py
@@ -4,7 +4,6 @@ from decimal import Decimal
 
 from django.apps.registry import Apps
 from django.db.backends.base.schema import BaseDatabaseSchemaEditor
-from django.db.models.fields.related import ManyToManyField
 from django.utils import six
 
 import _sqlite3
@@ -71,7 +70,7 @@ class DatabaseSchemaEditor(BaseDatabaseSchemaEditor):
         for field in create_fields:
             body[field.name] = field
             # Choose a default and insert it into the copy map
-            if not isinstance(field, ManyToManyField):
+            if not field.many_to_many:
                 mapping[field.column] = self.quote_value(
                     self.effective_default(field)
                 )
@@ -94,7 +93,7 @@ class DatabaseSchemaEditor(BaseDatabaseSchemaEditor):
             del body[field.name]
             del mapping[field.column]
             # Remove any implicit M2M tables
-            if isinstance(field, ManyToManyField) and field.rel.through._meta.auto_created:
+            if field.many_to_many and field.rel.through._meta.auto_created:
                 return self.delete_model(field.rel.through)
         # Work inside a new app registry
         apps = Apps()
@@ -173,7 +172,7 @@ class DatabaseSchemaEditor(BaseDatabaseSchemaEditor):
         table instead (for M2M fields)
         """
         # Special-case implicit M2M tables
-        if isinstance(field, ManyToManyField) and field.rel.through._meta.auto_created:
+        if field.many_to_many and field.rel.through._meta.auto_created:
             return self.create_model(field.rel.through)
         self._remake_table(model, create_fields=[field])
 
@@ -183,7 +182,7 @@ class DatabaseSchemaEditor(BaseDatabaseSchemaEditor):
         but for M2Ms may involve deleting a table.
         """
         # M2M fields are a special case
-        if isinstance(field, ManyToManyField):
+        if field.many_to_many:
             # For implicit M2M tables, delete the auto-created table
             if field.rel.through._meta.auto_created:
                 self.delete_model(field.rel.through)