[1.8.x] Fixed #26889 -- Fixed missing PostgreSQL index in SchemaEditor.add_field().

Backport of 2e4cfcd2b9a0984ad6c4087a5deebbf33413835c from master

django/db/backends/postgresql_psycopg2/schema.py

@@ -14,6 +14,12 @@ class DatabaseSchemaEditor(BaseDatabaseSchemaEditor):
     def quote_value(self, value):
         return psycopg2.extensions.adapt(value)
 
+    def add_field(self, model, field):
+        super(DatabaseSchemaEditor, self).add_field(model, field)
+        like_index_statement = self._create_like_index_sql(model, field)
+        if like_index_statement is not None:
+            self.deferred_sql.append(like_index_statement)
+
     def _model_indexes_sql(self, model):
         output = super(DatabaseSchemaEditor, self)._model_indexes_sql(model)
         if not model._meta.managed or model._meta.proxy or model._meta.swapped:

docs/releases/1.8.14.txt

@@ -0,0 +1,14 @@
+===========================
+Django 1.8.14 release notes
+===========================
+
+*Under development*
+
+Django 1.8.14 fixes several bugs in 1.8.13.
+
+Bugfixes
+========
+
+* Fixed missing ``varchar/text_pattern_ops`` index on ``CharField`` and
+  ``TextField`` respectively when using ``AddField`` on PostgreSQL
+  (:ticket:`26889`).

docs/releases/index.txt

@@ -25,6 +25,7 @@ versions of the documentation contain the release notes for any later releases.
 .. toctree::
    :maxdepth: 1
 
+   1.8.14
    1.8.13
    1.8.12
    1.8.11

tests/schema/tests.py

@@ -1551,6 +1551,33 @@ class SchemaTests(TransactionTestCase):
         with connection.schema_editor() as editor:
             editor.add_field(Author, new_field)
 
+    @unittest.skipUnless(connection.vendor == 'postgresql', "PostgreSQL specific")
+    def test_add_indexed_charfield(self):
+        field = CharField(max_length=255, db_index=True)
+        field.set_attributes_from_name('nom_de_plume')
+        with connection.schema_editor() as editor:
+            editor.create_model(Author)
+            editor.add_field(Author, field)
+        indexes = self.get_constraints_for_column(Author, 'nom_de_plume')
+        # Should create two indexes; one for like operator.
+        self.assertEqual(len(indexes), 2)
+        # Check that one of the indexes ends with `_like`
+        like_index = [x for x in indexes if x.endswith('_like')]
+        self.assertEqual(1, len(like_index), 'Index with the operator class is missing')
+
+    @unittest.skipUnless(connection.vendor == 'postgresql', "PostgreSQL specific")
+    def test_add_unique_charfield(self):
+        field = CharField(max_length=255, unique=True)
+        field.set_attributes_from_name('nom_de_plume')
+        with connection.schema_editor() as editor:
+            editor.create_model(Author)
+            editor.add_field(Author, field)
+        indexes = self.get_constraints_for_column(Author, 'nom_de_plume')
+        # Should create two indexes; one for like operator.
+        self.assertEqual(len(indexes), 2)
+        like_index = [x for x in indexes if x.endswith('_like')]
+        self.assertEqual(1, len(like_index), 'Index with the operator class is missing')
+
     @unittest.skipUnless(connection.vendor == 'postgresql', "PostgreSQL specific")
     def test_alter_field_add_index_to_charfield(self):
         # Create the table and verify no initial indexes.