prefactor: extract XPathContext#register_variables

lib/nokogiri/xml/searchable.rb

@@ -263,11 +263,9 @@ def xpath_internal(node, paths, handler, ns, binds)
       def xpath_impl(node, path, handler, ns, binds)
         ctx = XPathContext.new(node)
         ctx.register_namespaces(ns)
-        path = path.gsub("xmlns:", " :") unless Nokogiri.uses_libxml?
+        ctx.register_variables(binds)
 
-        binds&.each do |key, value|
-          ctx.register_variable(key.to_s, value)
-        end
+        path = path.gsub("xmlns:", " :") unless Nokogiri.uses_libxml?
 
         ctx.evaluate(path, handler)
       end

lib/nokogiri/xml/xpath_context.rb

@@ -6,9 +6,20 @@ class XPathContext
       ###
       # Register namespaces in +namespaces+
       def register_namespaces(namespaces)
-        namespaces.each do |k, v|
-          k = k.to_s.gsub(/.*:/, "") # strip off 'xmlns:' or 'xml:'
-          register_ns(k, v)
+        namespaces.each do |key, value|
+          key = key.to_s.gsub(/.*:/, "") # strip off 'xmlns:' or 'xml:'
+
+          register_ns(key, value)
+        end
+      end
+
+      def register_variables(binds)
+        return if binds.nil?
+
+        binds.each do |key, value|
+          key = key.to_s
+
+          register_variable(key, value)
         end
       end
     end