bug#6960: mv refuses to move a symlink over a hard link to the same file

[Matt McCutchen]

If mv is asked to move a symlink over a hard link to the same file, it
fails with the message, "A and B are the same file".  There is no reason
why it should complain rather than perform the move.  Example:

$ ~/coreutils/coreutils.usr/bin/mv --version
mv (GNU coreutils) 8.5.143-77702
Copyright (C) 2010 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

Written by Mike Parker, David MacKenzie, and Jim Meyering.
$ touch New_York
$ ln New_York localtime
$ ln -s New_York localtime.new
$ ls -l
total 0
-rw------- 2 matt matt 0 2010-08-31 17:10 New_York
-rw------- 2 matt matt 0 2010-08-31 17:10 localtime
lrwxrwxrwx 1 matt matt 8 2010-08-31 17:11 localtime.new -> New_York
$ ~/coreutils/coreutils.usr/bin/mv localtime.new localtime
/home/matt/coreutils/coreutils.usr/bin/mv: `localtime.new' and `localtime' are 
the same file

-- 
Matt