Git whitespace errors

By default, trailing whitespaces (including lines that consist solely of whitespaces) and a space character that is immediately followed by a tab character inside the initial indent of the line are considered whitespace errors.

Git, with setting core.whitespace, comes preset to detect and fix some whitespace issues. It can look for six primary whitespace issues — three are enabled by default and can be turned off, and three are disabled by default but can be activated.

The three that are turned on by default:

• blank-at-eol, which looks for spaces at the end of a line (EOL);
• blank-at-eof, which notices blank lines at the end of a file (EOF);
• space-before-tab, which looks for spaces before tabs at the beginning of a line.

trailing-space being a short-hand to cover both blank-at-eol and blank-at-eof.

The three that are disabled by default but can be turned on:

• indent-with-non-tab, which looks for lines that begin with spaces instead of tabs (and is controlled by the tabwidth option);
• tab-in-indent, which watches for tabs in the indentation portion of a line;
• cr-at-eol, which tells Git that carriage returns (CR: \r) at the end of lines are OK.

You can disable an option by prepending a - in front of its name, or use the default value by leaving it out of the setting string entirely.

For example, if you want all but space-before-tab to be set, you can do this:

git config --global core.whitespace \
    trailing-space,-space-before-tab,indent-with-non-tab,tab-in-indent,cr-at-eol

Or you can specify the customizing part only:

git config --global core.whitespace \
    -space-before-tab,indent-with-non-tab,tab-in-indent,cr-at-eol

Git will detect these issues when you run a git diff command and try to color them so you can possibly fix them before you commit.

git apply --whitespace / git config apply.whitespace

It will also use these values to help you when you apply patches with git apply. When you’re applying patches, you can ask Git to warn or error you if it’s applying patches with the specified whitespace issues:

git apply --whitespace=warn <patch>
git apply --whitespace=error <patch>      # a few such errors
git apply --whitespace=error-all <patch>  # all errors

Or

git config apply.whitespace warn
git config apply.whitespace error      # a few such errors
git config apply.whitespace error-all  # all errors

Or you can have Git try to automatically fix the issue before applying the patch:

git apply --whitespace=fix <patch>

Or

git config apply.whitespace fix

Or turning off the warning:

git apply --whitespace=nowarn <patch>

Or

git config apply.whitespace nowarn

git rebase

These options apply to the git rebase command as well. If you’ve committed whitespace issues but haven’t yet pushed upstream, you can have Git automatically fix whitespace issues as it’s rewriting the patches:

git rebase --whitespace=fix

More details about core.whitespace configuration please refer to Git Configuration.