The order of a mailing list's header matches is significant

Add a numerical index property to HeaderMatch objects, and change the
HeaderMatchSet manager to take the order into account.

Items can now be inserted and removed by index.

2 files changed, 44 insertions, 2 deletions

diff --git a/src/mailman/database/alembic/versions/d4fbb4fd34ca_header_match_order.py b/src/mailman/database/alembic/versions/d4fbb4fd34ca_header_match_order.py
new file mode 100644
index 000000000..00064bc1e
--- /dev/null
+++ b/src/mailman/database/alembic/versions/d4fbb4fd34ca_header_match_order.py
@@ -0,0 +1,40 @@
+"""Add a numerical index to sort header matches.
+
+Revision ID: d4fbb4fd34ca
+Revises: bfda02ab3a9b
+Create Date: 2016-02-01 15:57:09.807678
+
+"""
+
+# revision identifiers, used by Alembic.
+revision = 'd4fbb4fd34ca'
+down_revision = 'bfda02ab3a9b'
+
+import sqlalchemy as sa
+from alembic import op
+from mailman.database.helpers import is_sqlite
+
+
+def upgrade():
+    op.add_column(
+        'headermatch', sa.Column('index', sa.Integer(), nullable=True))
+    if not is_sqlite(op.get_bind()):
+        op.alter_column(
+            'headermatch', 'mailing_list_id',
+            existing_type=sa.INTEGER(), nullable=False)
+    op.create_index(
+        op.f('ix_headermatch_index'), 'headermatch', ['index'], unique=False)
+    op.create_index(
+        op.f('ix_headermatch_mailing_list_id'), 'headermatch',
+        ['mailing_list_id'], unique=False)
+
+
+def downgrade():
+    op.drop_index(
+        op.f('ix_headermatch_mailing_list_id'), table_name='headermatch')
+    op.drop_index(op.f('ix_headermatch_index'), table_name='headermatch')
+    if not is_sqlite(op.get_bind()):
+        op.alter_column(
+            'headermatch', 'mailing_list_id',
+            existing_type=sa.INTEGER(), nullable=True)
+        op.drop_column('headermatch', 'index')
diff --git a/src/mailman/database/tests/test_migrations.py b/src/mailman/database/tests/test_migrations.py
index 89173e26b..c3558abea 100644
--- a/src/mailman/database/tests/test_migrations.py
+++ b/src/mailman/database/tests/test_migrations.py
@@ -85,7 +85,9 @@ class TestMigrations(unittest.TestCase):
             sa.sql.column('header', sa.Unicode),
             sa.sql.column('pattern', sa.Unicode),
             )
-        # Downgrading.
+        # Bring the DB to the revision that is being tested.
+        alembic.command.downgrade(alembic_cfg, '42756496720')
+        # Test downgrading.
         config.db.store.execute(mlist_table.insert().values(id=1))
         config.db.store.execute(header_match_table.insert().values(
             [{'mailing_list_id': 1, 'header': hm[0], 'pattern': hm[1]}
@@ -97,7 +99,7 @@ class TestMigrations(unittest.TestCase):
         self.assertEqual(results[0].header_matches, test_header_matches)
         self.assertFalse(exists_in_db(config.db.engine, 'headermatch'))
         config.db.store.commit()
-        # Upgrading.
+        # Test upgrading.
         alembic.command.upgrade(alembic_cfg, '42756496720')
         results = config.db.store.execute(
             header_match_table.select()).fetchall()