[ticket-workflow] is restored to default on environment upgrade

[Ryan J Ollos]

I noticed that when upgrading the environment the following message always appears:

==== Upgrade Notice ====

The ticket Workflow is now configurable.

Your environment has been upgraded, but configured to use the original
workflow. It is recommended that you look at changing this configuration to use
basic-workflow.

On upgrading from Trac 1.0.x to the trunk, the [ticket-workflow] section is overwritten.

The problem is that every upgrade participant is executed when upgrading the environment, therefore trac.ticket.default_workflow.ConfigurableTicketWorkflow.upgrade_environment​ is always executed. The following change would fix the issue:

trac/env.py

@@ -731 +731 @@
                 raise BackupError(e)
 
         for participant in self.setup_participants:
-            self.log.info("%s.%s upgrading...", participant.__module__,
-                          participant.__class__.__name__)
-            participant.upgrade_environment()
-            # Database schema may have changed, so close all connections
-            DatabaseManager(self).shutdown()
+            if participant.environment_needs_upgrade():
+                self.log.info("%s.%s upgrading...", participant.__module__,
+                              participant.__class__.__name__)
+                participant.upgrade_environment()
+                # Database schema may have changed, so close all connections.
+                DatabaseManager(self).shutdown()
         del self.database_version
         return True