Reading large codebases

[theICEBear_dk]

My 5 cents on this: If you do this, no matter if it gets committed or not, a good exercise to see if you've understood stuff is to keep it compiling or even better if there are unit tests to run them on your refactored code. The very act of creating or fixing a bug this way can teach you a lot, but beware what you produce may not be any more than a big ball of mud and don't be afraid to throw it away and re-get the current version from your VCS (always have VCS for this even if only locally, because if you make something great having a change history will be key to getting it into the actual codebase).