selectors: no need to pass encoding on re() method

scrapy/selector/libxml2sel.py

@@ -54,7 +54,7 @@ class XPathSelector(object_ref):
     def re(self, regex):
         """Return a list of unicode strings by applying the regex over all
         current XPath selections, and flattening the results"""
-        return extract_regex(regex, self.extract(), 'utf-8')
+        return extract_regex(regex, self.extract())
 
     def extract(self):
         """Return a unicode string of the content referenced by the XPathSelector"""

scrapy/selector/lxmlsel.py

@@ -59,7 +59,7 @@ class XPathSelector(object_ref):
         return XPathSelectorList(result)
 
     def re(self, regex):
-        return extract_regex(regex, self.extract(), 'utf-8')
+        return extract_regex(regex, self.extract())
 
     def extract(self):
         try: