From d09ab26680112142cf46b94198be984f87edcafb Mon Sep 17 00:00:00 2001
From: Yorick Peterse <yorickpeterse@gmail.com>
Date: Tue, 15 Jul 2014 09:41:12 +0200
Subject: [PATCH] Support for the ancestor-or-self axis.

---
 lib/oga/xpath/evaluator.rb | 27 +++++++++++++++++++++++++--
 1 file changed, 25 insertions(+), 2 deletions(-)

diff --git a/lib/oga/xpath/evaluator.rb b/lib/oga/xpath/evaluator.rb
index 4d6e68d..94c9543 100644
--- a/lib/oga/xpath/evaluator.rb
+++ b/lib/oga/xpath/evaluator.rb
@@ -72,14 +72,16 @@ module Oga
       def on_axis(node, context)
         name, test = *node
 
-        return send("on_axis_#{name}", test, context)
+        handler = name.gsub('-', '_')
+
+        return send("on_axis_#{handler}", test, context)
       end
 
       def on_axis_ancestor(node, context)
         nodes = XML::NodeSet.new
 
         context.each do |xml_node|
-          while xml_node.respond_to?(:parent) and xml_node.parent
+          while has_parent?(xml_node)
             xml_node = xml_node.parent
 
             if node_matches?(xml_node, node)
@@ -92,6 +94,23 @@ module Oga
         return nodes
       end
 
+      def on_axis_ancestor_or_self(node, context)
+        nodes = XML::NodeSet.new
+
+        context.each do |xml_node|
+          while has_parent?(xml_node)
+            if node_matches?(xml_node, node)
+              nodes << xml_node
+              break
+            end
+
+            xml_node = xml_node.parent
+          end
+        end
+
+        return nodes
+      end
+
       def child_nodes(nodes)
         children = XML::NodeSet.new
 
@@ -121,6 +140,10 @@ module Oga
 
         return name_matches && ns_matches
       end
+
+      def has_parent?(node)
+        return node.respond_to?(:parent) && !!node.parent
+      end
     end # Evaluator
   end # XPath
 end # Oga