We have a feature branch right now in development that must not be deployed to production. At the moment there is nothing that would prevent such a mistake from happening.
Deployment happens manually at the moment (SVN export + FTP to production). Migration to a better model is planned but not available in the short term.
Now when you work on a branch locally, then export and upload the files it is really easy to accidentally deploy the wrong branch.
What are some easy and light-weight ways to prevent accidental deployments? We also would be happy with preventing accidental code execution. Downtime is much more acceptable than execution of the feature branches code. So it would be OK for the app to refuse to work in production. This would be noticed right away.