tests/reference

   1 #!/bin/sh
   2 # Ensure that reference compressed files are still decompressible, and
   3 # that their corresponding inputs still compress to precisely the same bytes.
   4 # For a "normal" compression program, one must not require that the encoded
   5 # bytes remain the same. The compression algorithm may change. What normally
   6 # matters is solely that the decompressed result is the same as the input
   7 # to the compressor. However, here, with gzip's current moribund state,
   8 # it is fine to require that. In particular, this test ensures that
   9 # a CRC-perf change doesn't accidentally cause trouble. It's not enough
  10 # that gzip decompress files the compressor has just created: it must
  11 # continue to decompress old compressed outputs, too.
  12
  13 # Copyright 2024 Free Software Foundation, Inc.
  14
  15 # This program is free software: you can redistribute it and/or modify
  16 # it under the terms of the GNU General Public License as published by
  17 # the Free Software Foundation, either version 3 of the License, or
  18 # (at your option) any later version.
  19
  20 # This program is distributed in the hope that it will be useful,
  21 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  22 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  23 # GNU General Public License for more details.
  24
  25 # You should have received a copy of the GNU General Public License
  26 # along with this program.  If not, see <https://www.gnu.org/licenses/>.
  27 # limit so don't run it by default.
  28
  29 . "${srcdir=.}/init.sh"; path_prepend_ ..
  30
  31 fail=0
  32
  33 cat <<EOF > exp || framework_failure_
  34 : 1f 8b 08 00 00 00 00 00 00 03 03 00 00 00 00 00 00 00 00 00
  35 a: 1f 8b 08 00 00 00 00 00 00 03 4b 04 00 43 be b7 e8 01 00 00 00
  36 b: 1f 8b 08 00 00 00 00 00 00 03 4b 02 00 f9 ef be 71 01 00 00 00
  37 c: 1f 8b 08 00 00 00 00 00 00 03 4b 06 00 6f df b9 06 01 00 00 00
  38 yyy: 1f 8b 08 00 00 00 00 00 00 03 ab ac ac 04 00 ea 81 45 73 03 00 00 00
  39 zzzzzzzzzzz: 1f 8b 08 00 00 00 00 00 00 03 ab aa 82 03 00 55 97 5b a7 0b 00 00 00
  40 EOF
  41
  42 # Ensure that compressing these simple strings always produces the same bytes.
  43 # If using "od" is not portable enough, consider using this:
  44 # perl -ne 'printf "%02x ", ord($_) for split //'
  45 for i in '' a b c yyy zzzzzzzzzzz; do
  46   echo $i: $(printf %s "$i" | gzip | od -An -tx1 | tr -d '\n')
  47 done > out || framework_failure_
  48
  49 compare exp out || fail=1
  50
  51 # Each output stream must inflate the original input.
  52 for i in '' a b c yyy zzzzzzzzzzz; do
  53   in=$(printf %s "$i" | gzip | gzip -d)
  54   test "$i" = "$in" || fail=1
  55 done
  56
  57 Exit $fail