Cannot checkout after setting the eol attribute

Hi,

I specified the `eol` attribute on some files recently and the behavior of Git is very strange.

Here is the set of commands to set up the repository used for the discussion:

    git init
    echo $'dos\r' > dos
    git add dos
    git commit -m "dos newlines"
    echo "dos -crlf" > .gitattributes
    git add .gitattributes
    git commit -m "add attributes"
    echo "dos eol=crlf" > .gitattributes
    git add .gitattributes
    git commit -m "set eol attribute instead"

The following behaviors are observed:

  - `git reset --hard` does not make the working directory clean; and
  - `git rebase` gets *very* confused about the diffs in the working
    tree because `git stash` can't reset the working tree;

There are probably other oddities lingering about as well. If I commit what Git thinks is the difference, the diff (with invisibles made visible) is:

    % git diff | cat -A
    diff --git a/dos b/dos$
    index fde2310..4723a1b 100644$
    --- a/dos$
    +++ b/dos$
    @@ -1 +1 @@$
    -dos^M$
    +dos$

Seen in 2.9.5 and 2.14.0.rc1.

--Ben