How to ignore trailing whitespace errors with git stash

Question

I have an unusual problem with git. I've pulled from a repo I haven't used in awhile, and for simplicity let's say I have two branches, develop and master. I was already in develop, and checked out master. I made no changes, I was just looking at the files. When I went to checkout develop, I could not because README.md was modified. Git diff showed the whole file was changed, with identical content, so I thought that was some sort of whitespace error.

I did git checkout -- README.md, and it still appeared modified. So then I tried git stash -p (so I could just stash that file). That gave me:

warning: 3 lines add whitespace errors.

It went on to say:

warning: squelched 55 whitespace errors
warning: 60 lines add whitespace errors.

And the file is still modified.

Is there any way to get around these errors? What could be causing it?

Answer 1

As you mentioned above, the issue is named trailing whitespace.
Git has several ways to handle whitespace. You can read about it here:
https://git-scm.com/book/en/v2/Customizing-Git-Git-Configuration#_formatting_and_whitespace

You can try and set the configuration values:

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

When git pops up content from a stash, it's adding it back to the working directory using the apply command, so you can disable the apply warning with this configuration

git config --global apply.whitespace nowarn
or 
git config --global core.whitespace fix

#core.whitespace A comma separated list of common whitespace problems to notice.
git diff will use color.diff.whitespace to highlight them,
and git apply --whitespace=error will consider them as errors.

You can prefix - to disable any of them (e.g. -trailing-space):

###blank-at-eol treats trailing whitespaces at the end of the line as an error (enabled by default).

###space-before-tab treats a space character that appears immediately before a tab character in the initial indent part of the line as an error (enabled by default).

###indent-with-non-tab treats a line that is indented with space characters instead of the equivalent tabs as an error (not enabled by default).

###tab-in-indent treats a tab character in the initial indent part of the line as an error (not enabled by default).

###blank-at-eof treats blank lines added at the end of file as an error (enabled by default).

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

###cr-at-eol treats a carriage-return at the end of line as part of the line terminator, i.e. with it, trailing-space does not trigger if the character before such a carriage-return is not a whitespace (not enabled by default).

###tabwidth=<n> tells how many character positions a tab occupies; this is relevant for indent-with-non-tab and when Git fixes tab-in-indent errors. The default tab width is 8. Allowed values are 1 to 63.