Git：从一个分支的给定文件中删除所有更改的最佳方法

I have a bit of a messy branch with 20 or so commits, and I'm preparing for a merge back to master. I've rebased it off master, and looking closer, I realise that there are files being modified in ways that are totally irrelevant to this branch, and not ready to be committed. The changes to those files aren't confined to specific commits.I have a bit of a messy branch with 20 or so co