Sort nodeset on demand

lib/rexml/functions.rb

@@ -85,9 +85,9 @@ def get_namespace( node_set = nil )
  if node_set == nil
  yield @context[:node] if @context[:node].respond_to?(:namespace)
  else
- if node_set.respond_to? :each
+ if node_set.kind_of? Array
  result = []
- node_set.each do |node|
+XPathParser.sort(node_set).each do |node|
  result << yield(node) if node.respond_to?(:namespace)
  end
  result
@@ -149,7 +149,7 @@ def string( object=@context[:node] )
  else
  case object
  when Array
- string(object[0])
+ string(XPathParser.sort(object).first)
  when Float
  if object.nan?
  "NaN"

lib/rexml/xpath_parser.rb

@@ -156,7 +156,7 @@ def match(path_stack, node)
  result = expr(path_stack, nodeset)
  case result
  when Array # nodeset
-result.uniq
+XPathParser.sort(result)
  else
  [result]
  end
@@ -323,7 +323,7 @@ def expr( path_stack, nodeset, context=nil )
  # If result is a nodeset, apply following predicates
  path_stack.unshift(:node)
  nodeset = step(path_stack) do
- [:iterate_nodesets, [result]]
+ [:iterate_nodesets, [XPathParser.sort(result)]]
  end
  else
  return result
@@ -571,6 +571,7 @@ def split_positional_predicates(predicates)
  end
 
  # Performs an axis scanning step.
+ # Returns an unordered non-duplicated nodeset of matching nodes.
  # The caller provides a scanner method and its argument, which determines the axis to scan and the nodes to scan from:
  # step(path_stack) { [scanner_method, scanner_argument] }
  # Scanner methods are called with `(scanner_argument, tester_block, selector)`
@@ -621,7 +622,7 @@ def step(path_stack, any_type: :element)
  nodes << node
  end
  end
- new_nodeset = sort(nodes.to_a)
+ new_nodeset = nodes.to_a
  ensure
  leave(:step, path_stack, new_nodeset) if @debug
  end
@@ -761,7 +762,7 @@ def leave(tag, *args)
  # in and out of function calls. If I knew what the index of the nodes was,
  # I wouldn't have to do this. Maybe add a document IDX for each node?
  # Problems with mutable documents. Or, rewrite everything.
- def sort(array_of_nodes)
+ def self.sort(array_of_nodes)
  return array_of_nodes if array_of_nodes.size <= 1
 
  new_arry = []

test/test_jaxen.rb

@@ -87,6 +87,13 @@ def process_value_of(context, variables, namespaces, value_of)
  xpath = value_of.attributes["select"]
  matched = XPath.match(context, xpath, namespaces, variables, strict: true)
 
+ # XPath.match can be a nodeset or a primitive value wrapped in an array.
+ # We need to unwrap primitive value because Functions doesn't accept array which is not a nodeset.
+ unless matched.all? { |node| node.is_a?(REXML::Node) }
+ assert_equal(1, matched.size, 'Primitive value should be a single value')
+ matched = matched.first
+ end
+
  message = user_message(context, xpath, matched)
  assert_equal(expected || "",
  REXML::Functions.string(matched),

test/xpath/test_base.rb

@@ -1499,5 +1499,21 @@ def test_descendant_axis_position_predicate_per_context_node
  result = XPath.match(xmldoc, "//a/descendant::b[1]")
  assert_equal(["b1", "b2"], result.map { |e| e.attributes["id"] })
  end
+
+ def test_reverse_axis_document_order_sort
+ doc = Document.new("<a><b>1</b><c>2</c><d>3</d><e/></a>")
+ assert_equal(["b", "c", "d"], XPath.match(doc, "//e/preceding-sibling::*").map(&:name))
+ assert_equal(["d"], XPath.match(doc, "//e/preceding-sibling::*[1]").map(&:name))
+ assert_equal(["b"], XPath.match(doc, "(//e/preceding-sibling::*)[1]").map(&:name))
+ end
+
+ def test_reverse_axis_function_argument_sort
+ doc = Document.new("<a><b>1</b><c>2</c><d>3</d><e/></a>")
+ assert_equal(["e"], XPath.match(doc, "//e[name(preceding-sibling::*)='b']").map(&:name))
+ assert_equal(["e"], XPath.match(doc, "//e[string(preceding-sibling::*)='1']").map(&:name))
+ assert_equal(["e"], XPath.match(doc, "//e[number(preceding-sibling::*)=1]").map(&:name))
+ assert_equal(["e"], XPath.match(doc, "//e[10 + preceding-sibling::* = 11]").map(&:name))
+ assert_equal(["e"], XPath.match(doc, "//e[preceding-sibling::* = '1']").map(&:name))
+ end
  end
 end