During my git trainings I often say that Git is land of freedom, and this is really true. Not many version control system would allow you to change something in history or permanently delete branch or tag. Git some times will prevent you from doing bad stuff, but you can easily say “shut up, I know what I’m doing” just by passing “force” flag (-f). Here I’m thinking about “force push” (aka “history rewrite”) when you can change something in repository history.
Local history rewrite is really useful when you are crafting yours commits. You can easily rearrange them, edit theirs content and commit message by using “rebase interactive”. I’m using this functionality on daily basis and cannot image working without freedom which it gives!
When we are talking about ability to rewrite remote history some people get really scared, especially in large organizations or those that needs to fallow some strict rules like banks and government orgs. From one hand Git and its “SHA-1 checksumming” ensures them that repository wasn’t changed … but from other hand Git allows changing something in past, of curse such change would be quickly spotted and can be fixed. Simple thought about occurrence of such event scares many enterprise companies, especially when they somehow find out about incident in Eclipse Foundation where almost all branches was accidentally deleted.
One of my first tasks in CollabNet was to provides a safety net against force pushes and branch deletion in Git. Our idea was to provide mechanism that could be easily activated and deactivated, will be accessible for regular users and administrators (regular user can resurrect rewritten history and deleted branch, administrators also can do that but also can permanently remove those entries) and protect whole (even deleted and rewritten history) against Git garbage collection. Base on those assumptions we come up with History Protection mechanism. If you want know more about it you can watch our short movie or read my other blog post. There is lots more cool Git Enterprise features coming from my CollabNet’s team in Potsdam 😉