class Expat < Formula
  desc "XML 1.0 parser"
  homepage "https://libexpat.github.io/"
  url "https://downloads.sourceforge.net/project/expat/expat/2.2.1/expat-2.2.1.tar.bz2"
  mirror "https://fossies.org/linux/www/expat-2.2.1.tar.bz2"
  sha256 "1868cadae4c82a018e361e2b2091de103cd820aaacb0d6cfa49bd2cd83978885"
  head "https://github.com/libexpat/libexpat.git"

  bottle do
    cellar :any
    sha256 "5703d1c1102f1228d6112eec9e127a43568bcf6ad2c5500195cfa6f14245c94a" => :sierra
    sha256 "31d368c2d0fbeee449e47af09aa28bc81b4f820a5ec0f240d0da2701fcfb2122" => :el_capitan
    sha256 "d58a80f9cca7e993f6b001fb0defeb68ced7b9cd05c39a787a355a4bf915d5f2" => :yosemite
  end

  keg_only :provided_by_osx, "macOS includes Expat 1.5"

  # Upstream commit from 18 Jun 2017 "configure.ac: Fix mis-detection of
  # getrandom on Debian GNU/kFreeBSD (#50)"
  # See https://github.com/libexpat/libexpat/commit/602e6c78ca750c082b72f8cdf4a38839b312959f
  patch :DATA

  def install
    system "./configure", "--prefix=#{prefix}",
                          "--mandir=#{man}"
    system "make", "install"
  end

  test do
    (testpath/"test.c").write <<-EOS.undent
      #include <stdio.h>
      #include "expat.h"

      static void XMLCALL my_StartElementHandler(
        void *userdata,
        const XML_Char *name,
        const XML_Char **atts)
      {
        printf("tag:%s|", name);
      }

      static void XMLCALL my_CharacterDataHandler(
        void *userdata,
        const XML_Char *s,
        int len)
      {
        printf("data:%.*s|", len, s);
      }

      int main()
      {
        static const char str[] = "<str>Hello, world!</str>";
        int result;

        XML_Parser parser = XML_ParserCreate("utf-8");
        XML_SetElementHandler(parser, my_StartElementHandler, NULL);
        XML_SetCharacterDataHandler(parser, my_CharacterDataHandler);
        result = XML_Parse(parser, str, sizeof(str), 1);
        XML_ParserFree(parser);

        return result;
      }
    EOS
    system ENV.cc, "test.c", "-I#{include}", "-L#{lib}", "-lexpat", "-o", "test"
    assert_equal "tag:str|data:Hello, world!|", shell_output("./test")
  end
end

__END__
--- a/configure
+++ b/configure
@@ -16341,7 +16341,7 @@ cat confdefs.h - <<_ACEOF >conftest.$ac_ext
   }

 _ACEOF
-if ac_fn_c_try_compile "$LINENO"; then :
+if ac_fn_c_try_link "$LINENO"; then :


 $as_echo "#define HAVE_GETRANDOM 1" >>confdefs.h