### Please describe the problem.

(small) identical files fail to unannex, leaving broken symlinks, except for the first copy.

### What steps will reproduce the problem?

* Have multiple identical files.  For example, run this, which creates four 6-byte files:

> echo Hello>file1.txt && cp file1.txt file2.txt && cp file1.txt file3.txt && cp file1.txt file4.txt

* Run this (git init needs credentials to have been specified though)

> git init && git-annex init && git-annex add

Now there are 4 symlinks, pointing to the same object:

> lrwxrwxrwx 1 186 Aug 16 15:54 file1.txt -> .git/annex/objects/31/XV/SHA256E-s6--66a045b452102c59d840ec097d59d9467e13a3f34f6494e539ffd32c1bb35f18.txt/SHA256E-s6--66a045b452102c59d840ec097d59d9467e13a3f34f6494e539ffd32c1bb35f18.txt

* Optionally run "git commit -a".  It doesn't affect the outcome.

* Run git-annex unannex

>     $ git annex unannex
>     unannex file1.txt ok
>     (Recording state in git...)
>     $ 

Now file1.txt is a normal 6-byte file again, but 2, 3, and 4 are broken symlinks:

    -rw-r----- 1   6 Aug 16 15:54 file1.txt
    lrwxrwxrwx 1 186 Aug 16 15:54 file2.txt -> .git/annex/objects/31/XV/SHA256E-s6--66a045b452102c59d840ec097d59d9467e13a3f34f6494e539ffd32c1bb35f18.txt/SHA256E-s6--66a045b452102c59d840ec097d59d9467e13a3f34f6494e539ffd32c1bb35f18.txt
    lrwxrwxrwx 1 186 Aug 16 15:54 file3.txt -> .git/annex/objects/31/XV/SHA256E-s6--66a045b452102c59d840ec097d59d9467e13a3f34f6494e539ffd32c1bb35f18.txt/SHA256E-s6--66a045b452102c59d840ec097d59d9467e13a3f34f6494e539ffd32c1bb35f18.txt
    lrwxrwxrwx 1 186 Aug 16 15:54 file4.txt -> .git/annex/objects/31/XV/SHA256E-s6--66a045b452102c59d840ec097d59d9467e13a3f34f6494e539ffd32c1bb35f18.txt/SHA256E-s6--66a045b452102c59d840ec097d59d9467e13a3f34f6494e539ffd32c1bb35f18.txt

    $ git-annex fsck
    fsck file2.txt 
      ** No known copies exist of file2.txt
    failed
    fsck file3.txt 
      ** No known copies exist of file3.txt
    failed
    fsck file4.txt 
      ** No known copies exist of file4.txt
    failed
    git-annex: fsck: 3 failed


### What version of git-annex are you using? On what operating system?

git-annex 4.20130802 package

on Debian GNU/Linux jessie/sid (testing), amd64.

> [[dup|done]] --[[Joey]] 
