puppet parser validate returns zero on nonexistent file (http://projects.puppetlabs.com/issues/15494)

gistfile1.diff

# half a fix
$ git diff ./lib/puppet/face/parser.rb
diff --git a/lib/puppet/face/parser.rb b/lib/puppet/face/parser.rb
index 3242fac..93642f7 100644
--- a/lib/puppet/face/parser.rb
+++ b/lib/puppet/face/parser.rb
@@ -42,8 +42,12 @@ Puppet::Face.define(:parser, '0.0.1') do
         end
       end
       files.each do |file|
-        Puppet[:manifest] = file
-        Puppet::Node::Environment.new(Puppet[:environment]).known_resource_types.clear
+        if File.readable?( file )
+          Puppet[:manifest] = file
+          Puppet::Node::Environment.new(Puppet[:environment]).known_resource_types.clear
+        else
+          puts "Can't access #{file}"
+        end
       end
       nil
     end