Git – Add only non-whitespace changes

gitwhitespace

I have my text editor to automatically trim trailing whitespace upon saving a file, and I am contributing to an open source project that has severe problems with trailing whitespace.

Every time I try to submit a patch I must first ignore all whitespace-only changes by hand, to choose only the relevant information. Not only that, but when I run git rebase I usually run into several problems because of them.

As such I would like to be able to add to index only non-whitespace changes, in a way similar that git add -p does, but without having to pick all the changes myself.

Does anyone know how to do this?

EDIT: I cannot change the way the project works, and they have decided, after discussing it on the mailing list, to ignore this.

Best Answer

@Frew solution wasn't quite what I needed, so this is the alias I made for the exact same problem:

alias.addnw=!sh -c 'git diff -U0 -w --no-color "$@" | git apply --cached --ignore-whitespace --unidiff-zero -'

Or you can simply run:

git diff -U0 -w --no-color | git apply --cached --ignore-whitespace --unidiff-zero -

Update

Added options -U0, and --unidiff-zero respectively to workaround context matching issues, according to this comment.

Basically it applies the patch which would be applied with add without whitespace changes. You will notice that after a git addnw your/file there will still be unstaged changes, it's the whitespaces left.

The --no-color isn't required but as I have colors set to always, I have to use it. Anyway, better safe than sorry.

Warning

While this trick works as-is, if you try to use it to drop blank line changes with --ignore-blank-lines then things get complicated. With this option, git diff will just drop some chunks, making the resulting patch bogus since the line numbers in the destination file are going to be off.

Related Solutions

Git – How to discard unstaged changes in Git

For all unstaged files in current working directory use:

git checkout -- .

For a specific file use:

git checkout -- path/to/file/to/revert

-- here to remove ambiguity (this is known as argument disambiguation).

For Git 2.23 onwards, one may want to use the more specific

git restore .

resp.

git restore path/to/file/to/revert

that together with git switch replaces the overloaded git checkout (see here), and thus removes the argument disambiguation.

Git – How to add a blank directory to a Git repository

Another way to make a directory stay (almost) empty (in the repository) is to create a .gitignore file inside that directory that contains these four lines:

# Ignore everything in this directory
*
# Except this file
!.gitignore

Then you don't have to get the order right the way that you have to do in m104's solution.

This also gives the benefit that files in that directory won't show up as "untracked" when you do a git status.

Making @GreenAsJade's comment persistent:

I think it's worth noting that this solution does precisely what the question asked for, but is not perhaps what many people looking at this question will have been looking for. This solution guarantees that the directory remains empty. It says "I truly never want files checked in here". As opposed to "I don't have any files to check in here, yet, but I need the directory here, files may be coming later".