When staging changes in interactive mode (git add -p), you have a number of options associated with single keys. y is yes, n is no, a is this and all remaini...
The default diff algorithm used by Git is pretty good, but it can get mislead by larger, complex changesets. The result is a noisier, misaligned diff output.
The author of the previous commit can be amended with the following command
Git provides a command explicitly intended for cleaning up (read: removing) untracked files from a local copy of a repository.