{ stdenv, fetchurl, zlib, apngSupport ? true }: assert zlib != null; let patchVersion = "1.6.34"; patch_src = fetchurl { url = "mirror://sourceforge/libpng-apng/libpng-${patchVersion}-apng.patch.gz"; sha256 = "1ha4npf9mfrzp0srg8a5amks5ww84xzfpjbsj8k3yjjpai798qg6"; }; whenPatched = stdenv.lib.optionalString apngSupport; in stdenv.mkDerivation rec { name = "libpng" + whenPatched "-apng" + "-${version}"; version = "1.6.34"; src = fetchurl { url = "mirror://sourceforge/libpng/libpng-${version}.tar.xz"; sha256 = "1xjr0v34fyjgnhvaa1zixcpx5yvxcg4zwvfh0fyklfyfj86rc7ig"; }; postPatch = whenPatched "gunzip < ${patch_src} | patch -Np1"; outputs = [ "out" "dev" "man" ]; outputBin = "dev"; propagatedBuildInputs = [ zlib ]; doCheck = stdenv.hostPlatform == stdenv.buildPlatform; passthru = { inherit zlib; }; meta = with stdenv.lib; { description = "The official reference implementation for the PNG file format" + whenPatched " with animation patch"; homepage = http://www.libpng.org/pub/png/libpng.html; license = licenses.libpng; platforms = platforms.all; maintainers = [ maintainers.vcunat maintainers.fuuzetsu ]; }; }