diff -r 6374b4ffe00c Lib/html/parser.py
--- a/Lib/html/parser.py	Fri Sep 02 23:19:52 2011 +0200
+++ b/Lib/html/parser.py	Sat Sep 03 12:12:15 2011 +0200
@@ -458,4 +458,4 @@
                     return '&'+s+';'
 
         return re.sub(r"&(#?[xX]?(?:[0-9a-fA-F]+|\w{1,8}));",
-                      replaceEntities, s, re.ASCII)
+                      replaceEntities, s, flags=re.ASCII)
diff -r 6374b4ffe00c Lib/test/test_htmlparser.py
--- a/Lib/test/test_htmlparser.py	Fri Sep 02 23:19:52 2011 +0200
+++ b/Lib/test/test_htmlparser.py	Sat Sep 03 12:12:15 2011 +0200
@@ -377,7 +377,8 @@
         p = html.parser.HTMLParser()
         self.assertEqual(p.unescape('&#bad;'),'&#bad;')
         self.assertEqual(p.unescape('&'),'&')
-
+        N = 1000
+        self.assertEqual(p.unescape('{ ' * N), '{ ' * N)
 
 def test_main():
     support.run_unittest(HTMLParserTestCase, HTMLParserTolerantTestCase)