libkml: Add HEAD build

Closes #15728.

Signed-off-by: Charlie Sharpsteen <source@sharpsteen.net>

Library/Formula/libkml.rb

@@ -5,7 +5,24 @@ class Libkml < Formula
   homepage 'http://code.google.com/p/libkml/'
   sha1 '3fa5acdc2b2185d7f0316d205002b7162f079894'
 
+  head 'http://libkml.googlecode.com/svn/trunk/', :using => :svn
+
+  if build.head?
+    depends_on :automake
+    depends_on :libtool
+  end
+
   def install
+
+    if build.head?
+      # The inreplace line below is only required until the patch in #issue 186
+      # is applied. http://code.google.com/p/libkml/issues/detail?id=186
+      # If the patch is applied, this find and replace will be unnecessary, but also
+      # harmless
+      inreplace 'configure.ac', '-Werror', ''
+      system "./autogen.sh"
+    end
+
     system "./configure", "--prefix=#{prefix}"
     system "make install"
   end