3 files changed, 42 insertions, 1 deletions

diff --git a/src/mailman/database/base.py b/src/mailman/database/base.py
index 37fe35eb9..1e71341e0 100644
--- a/src/mailman/database/base.py
+++ b/src/mailman/database/base.py
@@ -97,6 +97,24 @@ class StormBaseDatabase:
         """
         raise NotImplementedError
 
+    def _pre_reset(self, store):
+        """Clean up method for testing.
+
+        This method is called during the test suite just before all the model
+        tables are removed.  Override this to perform any database-specific
+        pre-removal cleanup.
+        """
+        pass
+
+    def _post_reset(self, store):
+        """Clean up method for testing.
+
+        This method is called during the test suite just after all the model
+        tables have been removed.  Override this to perform any
+        database-specific post-removal cleanup.
+        """
+        pass
+
     def _create(self, debug):
         # Calculate the engine url.
         url = expand(config.database.url, config.paths)
diff --git a/src/mailman/database/model.py b/src/mailman/database/model.py
index 173659269..eec88936f 100644
--- a/src/mailman/database/model.py
+++ b/src/mailman/database/model.py
@@ -49,11 +49,14 @@ class ModelMeta(PropertyPublisherMeta):
 
     @staticmethod
     def _reset(store):
+        from mailman.config import config
+        config.db._pre_reset(store)
         # Make sure this is deterministic, by sorting on the storm table name.
         classes = sorted(ModelMeta._class_registry,
                          key=attrgetter('__storm_table__'))
         for model_class in classes:
             store.find(model_class).remove()
+        config.db._post_reset(store)
 
 
 
diff --git a/src/mailman/database/postgresql.py b/src/mailman/database/postgresql.py
index b59165243..4e40558a4 100644
--- a/src/mailman/database/postgresql.py
+++ b/src/mailman/database/postgresql.py
@@ -25,6 +25,7 @@ __all__ = [
     ]
 
 
+from operator import attrgetter
 from pkg_resources import resource_string
 
 from mailman.database.base import StormBaseDatabase
@@ -38,10 +39,29 @@ class PostgreSQLDatabase(StormBaseDatabase):
         """See `BaseDatabase`."""
         table_query = ('SELECT table_name FROM information_schema.tables '
                        "WHERE table_schema = 'public'")
-        table_names = set(item[0] for item in 
+        table_names = set(item[0] for item in
                           store.execute(table_query))
         return 'version' in table_names
 
     def _get_schema(self):
         """See `BaseDatabase`."""
         return resource_string('mailman.database.sql', 'postgres.sql')
+
+    def _post_reset(self, store):
+        """PostgreSQL-specific test suite cleanup.
+
+        Reset the <tablename>_id_seq.last_value so that primary key ids
+        restart from zero for new tests.
+        """
+        from mailman.database.model import ModelMeta
+        classes = sorted(ModelMeta._class_registry,
+                         key=attrgetter('__storm_table__'))
+        # Recipe adapted from
+        # http://stackoverflow.com/questions/544791/
+        # django-postgresql-how-to-reset-primary-key
+        for model_class in classes:
+            store.execute("""\
+                SELECT setval('"{0}_id_seq"', coalesce(max("id"), 1),
+                              max("id") IS NOT null)
+                       FROM "{0}";
+                """.format(model_class.__storm_table__))