#!/bin/sh
# Detect printf(3) failure even when it doesn't set stream error indicator

# Copyright (C) 2007 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/>.

prog="$abs_top_builddir/src/printf"

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

. $srcdir/../test-lib.sh
require_ulimit_

fail=0

# Up to coreutils-6.9, "printf %.Nf 0" would encounter an ENOMEM internal
# error from glibc's printf(3) function whenever N was large relative to
# the size of available memory.  As of Oct 2007, that internal stream-
# related failure was not reflected (for any libc I know of) in the usual
# stream error indicator that is tested by ferror.  The result was that
# while the printf command obviously failed (generated no output),
# it mistakenly exited successfully (exit status of 0).

# Testing it is tricky, because there is so much variance
# in quality for this corner of printf(3) implementations.
# Most implementations do attempt to allocate N bytes of storage.
# Using the maximum value for N (2^31-1) causes glibc to try to
# allocate almost 2^64 bytes, while freeBSD 6.1's implementation
# correctly outputs almost 2GB worth of 0's, which takes too long.
# We want to test implementations that allocate N bytes, but without
# triggering the above extremes.

# The compromise is to limit virtual memory to something reasonable,
# and to make an N-byte-allocating-printf require more than that, thus
# triggering the printf(3) misbehavior -- which, btw, is required by ISO C99.

( ulimit -v 10000
  "$prog" %20000000f 0 2>err | head -c 10 >out )

# Map this longer, and rarer, diagnostic to the common one.
# printf: cannot perform formatted output: Cannot allocate memory" \
sed 's/cannot perform .*/write error/' err > k && mv k err
case $(cat err) in
  "$prog: write error") diagnostic=y ;;
  '') diagnostic=n ;;
  *) diagnostic=unexpected ;;
esac
n_out=$(wc -c < out)

case $n_out:$diagnostic in
  10:n) ;; # ok, succeeds w/no diagnostic: FreeBSD 6.1
  0:y)  ;; # ok, glibc, when printf(3) fails with ENOMEM

  # 10:y) ;; # Fail: doesn't happen: nobody succeeds with a diagnostic
  # 0:n)  ;; # Fail pre-patch: no output, no diag
  *) fail=1;
esac

(exit $fail); exit $fail