From bcf9b174ff12cf9c4223c1964bb19ad7033066ee Mon Sep 17 00:00:00 2001
From: Raoul Snyman <raoul.snyman@saturnlaboratories.co.za>
Date: Thu, 25 Aug 2011 22:02:55 +0200
Subject: [PATCH] Fixed a bug where the version number saved to the database
 was incorrect. Added the ability to throw an error message and not load the
 database if the db is too new or incorrect.

---
 openlp/core/lib/db.py               | 29 ++++++++++++++++++++++++++---
 openlp/plugins/songs/lib/upgrade.py |  2 ++
 2 files changed, 28 insertions(+), 3 deletions(-)

diff --git a/openlp/core/lib/db.py b/openlp/core/lib/db.py
index 12f35ad1f..fb8a38b1f 100644
--- a/openlp/core/lib/db.py
+++ b/openlp/core/lib/db.py
@@ -36,6 +36,8 @@ from sqlalchemy.exc import SQLAlchemyError, InvalidRequestError, DBAPIError
 from sqlalchemy.orm import scoped_session, sessionmaker, mapper
 from sqlalchemy.pool import NullPool
 
+from openlp.core.lib import translate
+from openlp.core.lib.ui import critical_error_message_box
 from openlp.core.utils import AppLocation, delete_file
 
 log = logging.getLogger(__name__)
@@ -84,19 +86,22 @@ def upgrade_db(url, upgrade):
         version = 0
     else:
         version = int(version_meta.value)
+    if version > upgrade.__version__:
+        return version, upgrade.__version__
     version += 1
     while hasattr(upgrade, u'upgrade_%d' % version):
         log.debug(u'Running upgrade_%d', version)
         try:
             getattr(upgrade, u'upgrade_%d' % version)(session, metadata, tables)
-            version += 1
             version_meta.value = unicode(version)
         except SQLAlchemyError, DBAPIError:
             log.exception(u'Could not run database upgrade script "upgrade_%s"'\
                 ', upgrade process has been halted.', version)
             break
+        version += 1
     session.add(version_meta)
     session.commit()
+    return int(version_meta.value), upgrade.__version__
 
 def delete_database(plugin_name, db_file_name=None):
     """
@@ -186,8 +191,26 @@ class Manager(object):
                 unicode(settings.value(u'db database').toString()))
         settings.endGroup()
         if upgrade_mod:
-            upgrade_db(self.db_url, upgrade_mod)
-        self.session = init_schema(self.db_url)
+            db_ver, up_ver = upgrade_db(self.db_url, upgrade_mod)
+            if db_ver > up_ver:
+                critical_error_message_box(
+                    translate('OpenLP.Manager', 'Database Error'),
+                    unicode(translate('OpenLP.Manager', 'The database being '
+                        'loaded was created in a more recent version of '
+                        'OpenLP. The database is version %d, while OpenLP '
+                        'expects version %d. The database will not be loaded.'
+                        '\n\nDatabase: %s')) % \
+                        (db_ver, up_ver, self.db_url)
+                )
+                return
+        try:
+            self.session = init_schema(self.db_url)
+        except:
+            critical_error_message_box(
+                translate('OpenLP.Manager', 'Database Error'),
+                unicode(translate('OpenLP.Manager', 'OpenLP cannot load your '
+                    'database.\n\nDatabase: %s')) % self.db_url
+            )
 
     def save_object(self, object_instance, commit=True):
         """
diff --git a/openlp/plugins/songs/lib/upgrade.py b/openlp/plugins/songs/lib/upgrade.py
index 278b6fe86..56b04bb01 100644
--- a/openlp/plugins/songs/lib/upgrade.py
+++ b/openlp/plugins/songs/lib/upgrade.py
@@ -33,6 +33,8 @@ from sqlalchemy import Column, ForeignKey, Table, types
 from migrate import changeset
 from migrate.changeset.constraint import ForeignKeyConstraint
 
+__version__ = 1
+
 def upgrade_setup(metadata):
     """
     Set up the latest revision all tables, with reflection, needed for the