#!/bin/sh
# Ensure that sort --sort-random doesn't sort.

# Copyright (C) 2005, 2006 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/>.

if test "$VERBOSE" = yes; then
  set -x
  sort --version
fi

pwd=`pwd`
t0=`echo "$0"|sed 's,.*/,,'`.tmp; tmp=$t0/$$
trap 'status=$?; cd "$pwd" && chmod -R u+rwx $t0 && rm -rf $t0 && exit $status' 0
trap '(exit $?); exit $?' 1 2 13 15

framework_failure=0
mkdir -p $tmp || framework_failure=1
cd $tmp || framework_failure=1
seq 100 > in || framework_failure=1

if test $framework_failure = 1; then
  echo "$0: failure in testing framework" 1>&2
  (exit 1); exit 1
fi

fail=0

sort --random-sort in > out || fail=1

# Fail if the input is the same as the output.
# This is a probabilistic test :-)
# However, the odds of failure are very low: 1 in 100! (~ 1 in 10^158)
cmp in out > /dev/null && { fail=1; echo "not random?" 1>&2; }

# Fail if the sorted output is not the same as the input.
sort -n out > out1
cmp in out1 || { fail=1; echo "not a permutation" 1>&2; }

# If locale is available then use it to find a random non-C locale.
if (locale --version) > /dev/null 2>&1; then
  locale=`locale -a | sort --random-sort | awk '/^.._/{print;exit}'`
  LC_ALL=$locale sort --random-sort in > out1 || fail=1
  LC_ALL=$locale sort --random-sort in > out2 || fail=1

  # Fail if the output "randomly" is the same twice in a row.
  cmp out1 out2 > /dev/null && { fail=1; echo "not random with LC_ALL=$locale" 1>&2; }

  # Fail if the sorted output is not the same as the input.
  sort -n out > out1
  cmp in out1 || { fail=1; echo "not a permutation with LC_ALL=$locale" 1>&2; }
fi

(exit $fail); exit $fail