fixed when migration was running two times; fixed bug when rsm tried …

…to close already closed connection

raw_sql_migrate/engines/base.py

@@ -47,7 +47,6 @@ def commit(self):
         self._connection.commit()
 
     def execute(self, sql, params=None, return_result=None):
-
         if not params:
             params = {}
 

raw_sql_migrate/migration.py

@@ -54,15 +54,14 @@ def migrate(self, migration_direction):
         :param migration_direction: Direction towards which to migrate. Can be forward or backward.
         :return:
         """
-        
+
         assert self.module is not None
 
         if hasattr(self.module, migration_direction):
             handler = getattr(self.module, migration_direction)
             stdout.write('Migrating %s to migration %s in package %s\n' % (
                 migration_direction, self.py_module_name, self.py_package,
             ))
-            handler(database_api)
         else:
             raise IncorrectMigrationFile('Module %s has no %s function' % (
                 self.module, migration_direction,
@@ -76,7 +75,9 @@ def migrate(self, migration_direction):
                 self.delete_migration_history()
             database_api.commit()
         except Exception as e:
-            database_api.rollback()
+            if not database_api._connection.closed:
+                database_api.rollback()
+                database_api._connection.close()
             raise e
 
     def write_migration_history(self):