fixed bug with boolean results in lxml-based selectors

scrapy/selector/lxmlsel.py

@@ -55,7 +55,7 @@ class XPathSelector(object_ref):
         if hasattr(result, '__iter__'):
             result = [self.__class__(root=x, expr=xpath, namespaces=self.namespaces) \
                 for x in result]
-        elif result:
+        else:
             result = [self.__class__(root=result, expr=xpath, namespaces=self.namespaces)]
         return XPathSelectorList(result)
 

scrapy/tests/test_selector_lxml.py

@@ -45,6 +45,14 @@ class XPathSelectorTestCase(unittest.TestCase):
         self.assertEqual([x.extract() for x in xpath.select("concat(//input[@name='a']/@value, //input[@name='b']/@value)")],
                          [u'12'])
 
+    @libxml2debug
+    def test_selector_boolean_result(self):
+        body = "<p><input name='a'value='1'/><input name='b'value='2'/></p>"
+        response = TextResponse(url="http://example.com", body=body)
+        xs = HtmlXPathSelector(response)
+        self.assertEqual(xs.select("//input[@name='a']/@name='a'").extract(), [u'True'])
+        self.assertEqual(xs.select("//input[@name='a']/@name='n'").extract(), [u'False'])
+
     @libxml2debug
     def test_selector_same_type(self):
         """Test XPathSelector returning the same type in x() method"""