# macro: %png_fix path/to/name-of.png
#        for given png, fixes 'IDAT: invalid distance too far back', etc., 
#        see pngfix --help
#
#     -q do not output if macro fixed something or find unrecoverable error
#
#     this macro fails only if there is an unrecoverable error in the png
#     -- pngfix returns nonzero and $png.fixed doesn't exist; run pngfix
#     on that file, see return code and compare with pngfix --help output
%png_fix(q) \
  if test "x%1" == "x%%1"; then \
    echo "Missing argument in call to %%png_fix: path and name of png file." \
    exit 1 \
  fi \
  /usr/bin/pngfix %{-q: -qq} --suffix='.fixed' "%1" || true \
  mv "%1.fixed" "%1" \
  %nil
#
# macro: %png_fix_dir
#        for given directory, search *.png (recursively) and potentionaly
#        fix 'IDAT: invalid distance too far back', etc., see pngfix --help
#
#     -q do not output if pngfix fixed something or find unrecoverable error
#
%png_fix_dir(q) \
  if test "x%1" == "x%%1"; then \
    echo "Missing argument in call to %%png_fix_dir: dir where to search png files." \
    exit 1 \
  fi \
  for png in `find "%1" -iname '*.png'`; do \
    # -q will be propagated \
    %png_fix $png \
  done \
  %nil