#!/bin/sh
# This is just for the record.
# This test is not run.

# Copyright (C) 2003-2014 Free Software Foundation, Inc.

# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.

# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.

# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

exit 0

cat <<\EOF

Prior to 5.0.91, ...

The problem:
  On a VFAT file system with coreutils-5.0.90, 'mv FOO foo' removes the
  sole copy of the file named by both the source and destination arguments.

Demonstrate the problem, as root:

cd /tmp                                    \
  && dd if=/dev/zero of=1 bs=8192 count=50 \
  && mkdir mnt && mkfs -t vfat 1           \
  && mount -oloop 1 mnt && cd mnt          \
  && printf something important > foo      \
  && mv foo FOO
test -f FOO && echo PASS-1 || echo FAIL-1
ln foo bar
mv foo FOO
test -f FOO && echo PASS-2 || echo FAIL-2

And in case you actually do the above, you can do this to clean up:

  cd /tmp && umount /tmp/mnt && rm -r 1 mnt

Hey!  Can't create hard links on vfat.
The above 'ln' evokes an 'operation not permitted' failure.

This demonstrates the same thing with file system type 'umsdos'
No hard links:

cd /tmp                                    \
  && dd if=/dev/zero of=1 bs=8192 count=50 \
  && mkdir mnt && mkfs -t msdos 1          \
  && mount -t umsdos -oloop 1 mnt && cd mnt \
  && printf something important > foo      \
  && mv foo FOO
test -f FOO && echo PASS-1 || echo FAIL-1
ln foo bar
mv foo FOO
test -f FOO && echo PASS-2 || echo FAIL-2

EOF
