# macro: %png_fix_too_far_back path/to/name-of.png
#        for given png, fixes 'IDAT: invalid distance too far back'
#
#     -v output if macro fixed something or find unrecoverable error
#
%png_fix_too_far_back(v) \
  if test "x%1" == "x%%1"; then \
    echo "Missing argument in call to %%png_fix_too_far_back: path and name of png file." \
    exit 1 \
  fi \
  /usr/bin/png-fix-too-far-back "%1" \
  case $? in \
    0) # no need to fix \
      ;; \
    1) /usr/bin/png-fix-too-far-back -i "%1" \
       %{-v: echo "fixed: %1" } \
      ;; \
    2) %{-v: echo "unrecoverable error: %1" } \
      ;; \
    3) echo "%1 not found" \
      ;; \
  esac \
  %nil
#
# macro: %png_fix_too_far_back dir
#        for given directory, search *.png (recursively) and potentionaly
#        fix 'IDAT: invalid distance too far back'
#
#     -v output if macro fixed something or find unrecoverable error
#
%png_fix_too_far_back_dir(v) \
  if test "x%1" == "x%%1"; then \
    echo "Missing argument in call to %%png_fix_too_far_back_dir: dir where to search png files." \
    exit 1 \
  fi \
  for png in `find "%1" -iname '*.png'`; do \
    # -v will be propagated \
    %png_fix_too_far_back $png \
  done \
  %nil