#!/bin/sh
# Exercise an abort-inducing flaw in inotify-enabled tail -F.

# Copyright (C) 2009-2010 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
  tail --version
fi

. $srcdir/test-lib.sh

# 9 is a magic number, related to internal details of tail.c and hash.c
n=9
seq $n | xargs touch || framework_failure

debug='---disable-inotify -s .01'
debug=
tail $debug -qF $(seq $n) > out 2>&1 & pid=$!

# Wait until tail has started...
echo x > $n
until grep '^x$' out >/dev/null 2>&1; do :; done

mv 1 f || fail=1

# Wait for this diagnostic:
# tail: `1' has become inaccessible: No such file or directory
until grep inaccessible out >/dev/null 2>&1; do :; done

# Trigger the bug.  Before the fix, this would provoke the abort.
echo a > 1 || fail=1

# Wait up to 2s for the buggy tail to die,
# or for the "tail: `1' has appeared;  following end of new file" output
dead=0
for i in $(seq 10); do
  kill -0 $pid || { dead=1; break; }
  grep 'has appeared;' out > /dev/null && break
  sleep .2
done

# Fixed tail will not have aborted.  Kill it.
test $dead = 0 && kill -HUP $pid

wait $pid
st=$?

case $st in
  129) ;;
  *) echo tail died via unexpected signal: $st; fail=1;;
esac

cat out

Exit $fail