Upgrading Pootle
Pootle can easily be upgraded to newer versions to get the benefit of the newest versions. Here are some tips to make the process easier:
Familiarise yourself with important changes in Pootle over the versions. If you are upgrading to Pootle 2.x from Pootle 1.x, have a look at the migration page first, although some of the issues on this page could still be relevant.
Check the installation instructions for the newer version, and ensure that you have all the dependencies for the newer version. The package “south” is a requirement upgrading the database, for example.
If you are still using SQLite as your Pootle 2 database, you should look into doing a database migration to MySQL or Postgres for better performance. It is recommended to do this with Pootle 2.0.6 before migrating to Pootle 2.1 (the upgrade will be faster this way). Don't perform a Pootle version upgrade at the same time as a database migration. Finish the database migration completely before upgrading Pootle (or the other way round).
Always make backups of all your translation files (your whole podirectory), and your settings (localsettings.py). With Pootle 2.1 there is a way to synchronise all translation files with the database from the command line.
Make a backup of your complete database using the appropriate dump command for your database system.
You probably want to use your old localsettings.py with the new Pootle version, or make all the same changes to the file that came with the version you are upgrading to. When you start the new version of Pootle, you want to be sure that your podirectory and database settings are correct. If you reuse your old localsettings.py, you might want to look for any new settings that are available in the new version that you might want to configure. For example, the setting CONTACT_EMAIL was introduced in Pootle 2.1 - that would be missing from a settings file from Pootle 2.0.
Once you have the new code configured to run in your web server using the correct localsettings.py, Pootle should perform the necessary upgrade when the first page is requested.
updatedb management command.
Other changes you made to Pootle
If you made any changes to Pootle code, templates or styling, it will depend entirely on the details of these changes how you migrate them to the new Pootle version.
A diff from the original Pootle package you modified would allow you to keep track of your changes. Changes to the base template is likely to work fine, but changes to details will need individual inspection to see if they can apply cleanly or have to be reimplemented on the new version of Pootle.