test: add coverage for attribute namespace after reparenting

also use xmlNodePtr->properties in place of xmlElementPtr->attributes
because it's clearer and requires less type gymnastics

ext/nokogiri/xml_node.c

@@ -36,6 +36,7 @@ static void
 relink_namespace(xmlNodePtr reparented)
 {
   xmlNodePtr child;
+  xmlAttrPtr attr;
 
   if (reparented->type != XML_ATTRIBUTE_NODE &&
       reparented->type != XML_ELEMENT_NODE) { return; }
@@ -132,10 +133,10 @@ relink_namespace(xmlNodePtr reparented)
   }
 
   if (reparented->type == XML_ELEMENT_NODE) {
-    child = (xmlNodePtr)((xmlElementPtr)reparented)->attributes;
-    while (NULL != child) {
-      relink_namespace(child);
-      child = child->next;
+    attr = reparented->properties;
+    while (NULL != attr) {
+      relink_namespace((xmlNodePtr)attr);
+      attr = attr->next;
     }
   }
 }

test/namespaces/test_namespaces_in_created_doc.rb

@@ -7,7 +7,7 @@ def setup
         super
         @doc = Nokogiri::XML('<fruit xmlns="ns:fruit" xmlns:veg="ns:veg" xmlns:xlink="http://www.w3.org/1999/xlink"/>')
         pear = @doc.create_element('pear')
-        bosc = @doc.create_element('bosc')
+        bosc = @doc.create_element('bosc', {"veg:any" => "none"})
         pear.add_child(bosc)
         @doc.root << pear
         @doc.root.add_child('<orange/>')
@@ -38,6 +38,9 @@ def test_created_parent_default_ns
       def test_created_grandparent_default_ns
         assert_equal 'ns:fruit', check_namespace(@doc.root.elements[0].elements[0])
       end
+      def test_created_attribute_with_ns
+        assert_equal 'ns:veg', check_namespace(@doc.root.elements[0].elements[0].attribute_nodes.first)
+      end
       def test_created_parent_nondefault_ns
         assert_equal 'ns:veg',   check_namespace(@doc.root.elements[2])
       end