From f1aa58479cdc6051dd2e97feca2d584c43aee1e7 Mon Sep 17 00:00:00 2001
From: hui shang <shangdahao@gmail.com>
Date: Thu, 28 Dec 2017 07:56:24 +0800
Subject: [PATCH] Fixed #28714 -- Added system checks for invalid model field
 names in Meta.indexes.

Thanks Gabriel for the report and Adam Johnson for the review.
---
 django/db/models/base.py                  |  7 +++
 docs/ref/checks.txt                       |  6 +--
 tests/invalid_models_tests/test_models.py | 53 +++++++++++++++++++++++
 3 files changed, 63 insertions(+), 3 deletions(-)

diff --git a/django/db/models/base.py b/django/db/models/base.py
index 36be70beb5..2588ee3ff6 100644
--- a/django/db/models/base.py
+++ b/django/db/models/base.py
@@ -1203,6 +1203,7 @@ class Model(metaclass=ModelBase):
             errors += [
                 *cls._check_index_together(),
                 *cls._check_unique_together(),
+                *cls._check_indexes(),
                 *cls._check_ordering(),
             ]
 
@@ -1474,6 +1475,12 @@ class Model(metaclass=ModelBase):
                 errors.extend(cls._check_local_fields(fields, "unique_together"))
             return errors
 
+    @classmethod
+    def _check_indexes(cls):
+        """Check the fields of indexes."""
+        fields = [field for index in cls._meta.indexes for field, _ in index.fields_orders]
+        return cls._check_local_fields(fields, 'indexes')
+
     @classmethod
     def _check_local_fields(cls, fields, option):
         from django.db import models
diff --git a/docs/ref/checks.txt b/docs/ref/checks.txt
index 9b3f1be356..db86c49ee0 100644
--- a/docs/ref/checks.txt
+++ b/docs/ref/checks.txt
@@ -265,16 +265,16 @@ Models
 * **models.E009**: All ``index_together`` elements must be lists or tuples.
 * **models.E010**: ``unique_together`` must be a list or tuple.
 * **models.E011**: All ``unique_together`` elements must be lists or tuples.
-* **models.E012**: ``index_together/unique_together`` refers to the
+* **models.E012**: ``indexes/index_together/unique_together`` refers to the
   nonexistent field ``<field name>``.
-* **models.E013**: ``index_together/unique_together`` refers to a
+* **models.E013**: ``indexes/index_together/unique_together`` refers to a
   ``ManyToManyField`` ``<field name>``, but ``ManyToManyField``\s are not
   supported for that option.
 * **models.E014**: ``ordering`` must be a tuple or list (even if you want to
   order by only one field).
 * **models.E015**: ``ordering`` refers to the nonexistent field
   ``<field name>``.
-* **models.E016**: ``index_together/unique_together`` refers to field
+* **models.E016**: ``indexes/index_together/unique_together`` refers to field
   ``<field_name>`` which is not local to model ``<model>``.
 * **models.E017**: Proxy model ``<model>`` contains model fields.
 * **models.E018**: Autogenerated column name too long for field ``<field>``.
diff --git a/tests/invalid_models_tests/test_models.py b/tests/invalid_models_tests/test_models.py
index 4a3e5e3a02..71e1b83a3f 100644
--- a/tests/invalid_models_tests/test_models.py
+++ b/tests/invalid_models_tests/test_models.py
@@ -219,6 +219,59 @@ class UniqueTogetherTests(SimpleTestCase):
         ])
 
 
+@isolate_apps('invalid_models_tests')
+class IndexesTests(SimpleTestCase):
+
+    def test_pointing_to_missing_field(self):
+        class Model(models.Model):
+            class Meta:
+                indexes = [models.Index(fields=['missing_field'], name='name')]
+
+        self.assertEqual(Model.check(), [
+            Error(
+                "'indexes' refers to the nonexistent field 'missing_field'.",
+                obj=Model,
+                id='models.E012',
+            ),
+        ])
+
+    def test_pointing_to_m2m_field(self):
+        class Model(models.Model):
+            m2m = models.ManyToManyField('self')
+
+            class Meta:
+                indexes = [models.Index(fields=['m2m'], name='name')]
+
+        self.assertEqual(Model.check(), [
+            Error(
+                "'indexes' refers to a ManyToManyField 'm2m', but "
+                "ManyToManyFields are not permitted in 'indexes'.",
+                obj=Model,
+                id='models.E013',
+            ),
+        ])
+
+    def test_pointing_to_non_local_field(self):
+        class Foo(models.Model):
+            field1 = models.IntegerField()
+
+        class Bar(Foo):
+            field2 = models.IntegerField()
+
+            class Meta:
+                indexes = [models.Index(fields=['field2', 'field1'], name='name')]
+
+        self.assertEqual(Bar.check(), [
+            Error(
+                "'indexes' refers to field 'field1' which is not local to "
+                "model 'Bar'.",
+                hint='This issue may be caused by multi-table inheritance.',
+                obj=Bar,
+                id='models.E016',
+            ),
+        ])
+
+
 @isolate_apps('invalid_models_tests')
 class FieldNamesTests(SimpleTestCase):