Fixed #29198 -- Added migrate --plan option.

tests/migrations/test_migrations_plan/0001_initial.py

@@ -0,0 +1,28 @@
+from django.db import migrations, models
+
+
+def grow_tail(x, y):
+    """Grow salamander tail."""
+    pass
+
+
+def shrink_tail(x, y):
+    """Shrink salamander tail."""
+    pass
+
+
+class Migration(migrations.Migration):
+
+    initial = True
+
+    operations = [
+        migrations.CreateModel(
+            'Salamander',
+            [
+                ('id', models.AutoField(primary_key=True)),
+                ('tail', models.IntegerField(default=0)),
+                ('silly_field', models.BooleanField(default=False)),
+            ],
+        ),
+        migrations.RunPython(grow_tail, shrink_tail),
+    ]