expat: new homepage + head, strict audit with test

Closes Homebrew/homebrew#35723.

Signed-off-by: Mike McQuaid <mike@mikemcquaid.com>

Formula/expat.rb

@@ -1,11 +1,11 @@
-require 'formula'
-
 class Expat < Formula
-  homepage 'http://expat.sourceforge.net/'
-  url 'https://downloads.sourceforge.net/project/expat/expat/2.1.0/expat-2.1.0.tar.gz'
-  sha1 'b08197d146930a5543a7b99e871cba3da614f6f0'
+  homepage "http://www.libexpat.org"
+  url "https://downloads.sourceforge.net/project/expat/expat/2.1.0/expat-2.1.0.tar.gz"
+  sha1 "b08197d146930a5543a7b99e871cba3da614f6f0"
   revision 1
 
+  head ":pserver:anonymous:@expat.cvs.sourceforge.net:/cvsroot/expat", :using => :cvs
+
   bottle do
     cellar :any
     sha1 "94e147c1dd1016c67b5b6dad727b36cd64e9d210" => :yosemite
@@ -22,6 +22,45 @@ class Expat < Formula
     system "./configure", "--disable-debug", "--disable-dependency-tracking",
                           "--prefix=#{prefix}",
                           "--mandir=#{man}"
-    system "make install"
+    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", "-lexpat", "-o", "test"
+    assert_equal "tag:str|data:Hello, world!|", shell_output("./test")
   end
 end