[1.7.x] Fixed adding new GIS column in PostGIS 1.x migration

Refs #22451.
Backport of fb09a489c from master.

2 files changed, 94 insertions, 22 deletions

diff --git a/django/contrib/gis/db/backends/postgis/schema.py b/django/contrib/gis/db/backends/postgis/schema.py
index 181826789b..417bec6d42 100644
--- a/django/contrib/gis/db/backends/postgis/schema.py
+++ b/django/contrib/gis/db/backends/postgis/schema.py
@@ -10,36 +10,27 @@ class PostGISSchemaEditor(DatabaseSchemaEditor):
     sql_alter_geometry_column_not_null = "ALTER TABLE %(table)s ALTER COLUMN %(column)s SET NOT NULL"
     sql_add_spatial_index = "CREATE INDEX %(index)s ON %(table)s USING %(index_type)s (%(column)s %(ops)s)"
 
+    def __init__(self, *args, **kwargs):
+        super(PostGISSchemaEditor, self).__init__(*args, **kwargs)
+        self.geometry_sql = []
+
     def geo_quote_name(self, name):
         return self.connection.ops.geo_quote_name(name)
 
-    def create_model(self, model):
+    def column_sql(self, model, field, include_default=False):
         from django.contrib.gis.db.models.fields import GeometryField
-        # Do model creation first
-        super(PostGISSchemaEditor, self).create_model(model)
-        # Now add any spatial field SQL
-        sqls = []
-        for field in model._meta.local_fields:
-            if isinstance(field, GeometryField):
-                sqls.extend(self.spatial_field_sql(model, field))
-        for sql in sqls:
-            self.execute(sql)
-
-    def spatial_field_sql(self, model, field):
-        """
-        Takes a GeometryField and returns a list of SQL to execute to
-        create its spatial indexes.
-        """
-        output = []
+        if not isinstance(field, GeometryField):
+            return super(PostGISSchemaEditor, self).column_sql(model, field, include_default)
 
         if field.geography or self.connection.ops.geometry:
             # Geography and Geometry (PostGIS 2.0+) columns are
             # created normally.
-            pass
+            column_sql = super(PostGISSchemaEditor, self).column_sql(model, field, include_default)
         else:
+            column_sql = None, None
             # Geometry columns are created by the `AddGeometryColumn`
             # stored procedure.
-            output.append(
+            self.geometry_sql.append(
                 self.sql_add_geometry_column % {
                     "table": self.geo_quote_name(model._meta.db_table),
                     "column": self.geo_quote_name(field.column),
@@ -48,8 +39,9 @@ class PostGISSchemaEditor(DatabaseSchemaEditor):
                     "dim": field.dim,
                 }
             )
+
             if not field.null:
-                output.append(
+                self.geometry_sql.append(
                     self.sql_alter_geometry_column_not_null % {
                         "table": self.quote_name(model._meta.db_table),
                         "column": self.quote_name(field.column),
@@ -72,7 +64,7 @@ class PostGISSchemaEditor(DatabaseSchemaEditor):
                     index_ops = ''
             else:
                 index_ops = self.geom_index_ops
-            output.append(
+            self.geometry_sql.append(
                 self.sql_add_spatial_index % {
                     "index": self.quote_name('%s_%s_id' % (model._meta.db_table, field.column)),
                     "table": self.quote_name(model._meta.db_table),
@@ -81,5 +73,18 @@ class PostGISSchemaEditor(DatabaseSchemaEditor):
                     "ops": index_ops,
                 }
             )
+        return column_sql
 
-        return output
+    def create_model(self, model):
+        super(PostGISSchemaEditor, self).create_model(model)
+        # Create geometry columns
+        for sql in self.geometry_sql:
+            self.execute(sql)
+        self.geometry_sql = []
+
+    def add_field(self, model, field):
+        super(PostGISSchemaEditor, self).add_field(model, field)
+        # Create geometry columns
+        for sql in self.geometry_sql:
+            self.execute(sql)
+        self.geometry_sql = []
diff --git a/django/contrib/gis/tests/gis_migrations/test_operations.py b/django/contrib/gis/tests/gis_migrations/test_operations.py
new file mode 100644
index 0000000000..e9c4057575
--- /dev/null
+++ b/django/contrib/gis/tests/gis_migrations/test_operations.py
@@ -0,0 +1,67 @@
+from __future__ import unicode_literals
+
+from unittest import skipUnless
+
+from django.contrib.gis.tests.utils import HAS_SPATIAL_DB
+from django.db import connection, migrations, models
+from django.db.migrations.migration import Migration
+from django.db.migrations.state import ProjectState
+from django.test import TransactionTestCase
+
+if HAS_SPATIAL_DB:
+    from django.contrib.gis.db.models import fields
+
+
+@skipUnless(HAS_SPATIAL_DB, "Spatial db is required.")
+class OperationTests(TransactionTestCase):
+    available_apps = ["django.contrib.gis.tests.gis_migrations"]
+
+    def get_table_description(self, table):
+        with connection.cursor() as cursor:
+            return connection.introspection.get_table_description(cursor, table)
+
+    def assertColumnExists(self, table, column):
+        self.assertIn(column, [c.name for c in self.get_table_description(table)])
+
+    def apply_operations(self, app_label, project_state, operations):
+        migration = Migration('name', app_label)
+        migration.operations = operations
+        with connection.schema_editor() as editor:
+            return migration.apply(project_state, editor)
+
+    def set_up_test_model(self):
+        operations = [migrations.CreateModel(
+            "Neighborhood",
+            [
+                ("id", models.AutoField(primary_key=True)),
+                ('name', models.CharField(max_length=100, unique=True)),
+                ('geom', fields.MultiPolygonField(srid=4326, null=True)),
+            ],
+        )]
+        return self.apply_operations('gis', ProjectState(), operations)
+
+    def test_add_gis_field(self):
+        """
+        Tests the AddField operation with a GIS-enabled column.
+        """
+        project_state = self.set_up_test_model()
+        operation = migrations.AddField(
+            "Neighborhood",
+            "path",
+            fields.LineStringField(srid=4326, null=True, blank=True),
+        )
+        new_state = project_state.clone()
+        operation.state_forwards("gis", new_state)
+        with connection.schema_editor() as editor:
+            operation.database_forwards("gis", editor, project_state, new_state)
+        self.assertColumnExists("gis_neighborhood", "path")
+
+        # Test GeometryColumns when available
+        try:
+            from django.contrib.gis.models import GeometryColumns
+        except ImportError:
+            return
+        self.assertEqual(
+            GeometryColumns.objects.filter(**{GeometryColumns.table_name_col(): "gis_neighborhood"}).count(),
+            2
+        )