git diff shows ^M with color ui true

Question

I modified my .gitconfig in such a way that I have some colors when performing git diff:

$ cat .gitconfig 
[color]
ui = true

I'm working on an ubuntu machine and I edited some code using VIM. After editing a file a execute git diff, once with and once without ui=true.

Problem: in the first case I have ^M characters and the end of the edited lines. However, I don't see those when turning of color.ui or when looking with vim, cat, more.. at the manipulated file.

Answer 1

It is probably an encoding issue. The 'git diff' command is executing Vim thinking that the file format is Dos.

When you are using any other command, it is correctly recognized as a Unix file.

Can you try : :set fileformat=unix in your git diff window ?

I am not really sure this is the root cause, because I don't see the link with the ui option.

Answer 2

The problem was solved for me by setting core.whitespace to cr-at-eol

treats a carriage-return at the end of line as part of the line terminator (git-config docs)

This can be added to a per-project or global git config file as follows:

[core]
    whitespace = cr-at-eol

This solves the problem of hiding the ^M at the end of lines which were in the diff due to another non-line-ending change. The intention is not to ignore changes where the only difference is the line ending. I am on windows with core.autocrlf=true and so the line ending mismatch is expected.

My only caution is that I don't know if this will affect whether git flags up genuine changes in EOL which one might want to commit, but perhaps with autocrlf=true this is never going to be the case.

An alternative fix, more targeted (but slightly more hacky), is described here.

Answer 3

Please have a look at Github's excellent "Dealing with line endings" page:

https://help.github.com/articles/dealing-with-line-endings

You probably want to set core.autocrlf and then re-normalize your repository.