# This deco extension unpacks .msa disk images.

# .msa disk images are created by the Magic Shadow Archiver on Atari
# 16-bit platforms (ST, Falcon etc.).  As long as the .msa file is
# intact and the disk image has a recognisable FAT filesystem on it
# (which is untrue for some games, demos and "CD" disks) then the files
# should be unpacked OK.

# Dependencies:

# msa >= 0.1.0  http://hatari.sourceforge.net/files/msa-0.1.0.tar.gz
# mtools (tested on mcopy version 3.9.9)
# deco count_files function

decompress() {

  msa "${1}" >/dev/null 2>&1     # Convert .msa to .st
  success="$?"                   # 1 = converted .msa->.st 0 = other way

  beforefiles="`count_files .`"  # keep a record of how many files we have
  if [ "x${success}" = "x1" ]    # shouldn't need "x${...}" but just in case
  then
    MTOOLS_SKIP_CHECK=1 mcopy -i "${Main_name}.st" \
      -s -p -n ${Verbose+-v} ::. .

    eval "case \`count_files .\` in
    ${beforefiles})  exit 1 ;;   # mtools succeeds even if no files were
    esac"                        # extracted, so we signal an error

  else
    exit 1                       # msa not successfully converted, error
  fi
}