bug#13538: sort wrong

[XU Jian H]

$ cat log
/VOBS/MediaGW/gw/src/cha
/VOBS/MediaGW/gw/src/res
/VOBS/MediaGW/gw/src/res
/VOBS/MediaGW/gw/src/cha
/VOBS/MediaGW/gw/src/cha
/VOBS/MediaGW/gw/src/cha
/VOBS/MediaGW/gw/src@@/m
/VOBS/MediaGW/gw/src@@/m
/VOBS/MediaGW/gw/src@@/m

$ ~/bin/sort --version
sort (GNU coreutils) 8.20
Copyright (C) 2012 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 Haertel and Paul Eggert.

$ ~/bin/sort log
/VOBS/MediaGW/gw/src/cha
/VOBS/MediaGW/gw/src/cha
/VOBS/MediaGW/gw/src/cha
/VOBS/MediaGW/gw/src/cha
/VOBS/MediaGW/gw/src@@/m
/VOBS/MediaGW/gw/src@@/m
/VOBS/MediaGW/gw/src@@/m
/VOBS/MediaGW/gw/src/res
/VOBS/MediaGW/gw/src/res

But I expect the result should be:
/VOBS/MediaGW/gw/src/cha
/VOBS/MediaGW/gw/src/cha
/VOBS/MediaGW/gw/src/cha
/VOBS/MediaGW/gw/src/cha
/VOBS/MediaGW/gw/src/res
/VOBS/MediaGW/gw/src/res
/VOBS/MediaGW/gw/src@@/m
/VOBS/MediaGW/gw/src@@/m
/VOBS/MediaGW/gw/src@@/m

regards
xujian