patch against Python 3.3 source to re-enable u'' prefixes

py3_unicode_prefix.patch

diff -r f1cafe6f7834 Lib/test/test_builtin.py
--- a/Lib/test/test_builtin.py  Sun Nov 20 16:01:35 2011 +0100
+++ b/Lib/test/test_builtin.py  Fri Dec 09 14:04:31 2011 -0500
@@ -437,6 +437,14 @@
         self.assertRaises(TypeError, eval, ())
         self.assertRaises(SyntaxError, eval, bom[:2] + b'a')
 
+        # test 2.x u'...' syntax
+        self.assertEqual(eval('u"abc"'), "abc")
+        self.assertEqual(eval(r'ur"a\bc"'), "a\\bc")
+        self.assertRaises(SyntaxError, eval, 'bu"abc"')
+        self.assertRaises(SyntaxError, eval, 'ub"abc"')
+        self.assertRaises(SyntaxError, eval, 'ru"abc"')
+
+
     def test_general_eval(self):
         # Tests that general mappings can be used for the locals argument
 
diff -r f1cafe6f7834 Parser/tokenizer.c
--- a/Parser/tokenizer.c        Sun Nov 20 16:01:35 2011 +0100
+++ b/Parser/tokenizer.c        Fri Dec 09 14:04:31 2011 -0500
@@ -1412,8 +1412,8 @@
     /* Identifier (most frequent token!) */
     nonascii = 0;
     if (is_potential_identifier_start(c)) {
-        /* Process b"", r"" and br"" */
-        if (c == 'b' || c == 'B') {
+        /* Process u"", b"", r"", ur"" and br"" */
+        if (c == 'b' || c == 'B' || c == 'u' || c == 'U') {
             c = tok_nextc(tok);
             if (c == '"' || c == '\'')
                 goto letter_quote;
diff -r f1cafe6f7834 Python/ast.c
--- a/Python/ast.c      Sun Nov 20 16:01:35 2011 +0100
+++ b/Python/ast.c      Fri Dec 09 14:04:31 2011 -0500
@@ -3748,6 +3748,10 @@
             quote = *++s;
             *bytesmode = 1;
         }
+        else if (quote == 'u' || quote == 'U') {
+            /* this is parsed for 2.x compatibility, but ignored. */
+            quote = *++s;
+        }
         if (quote == 'r' || quote == 'R') {
             quote = *++s;
             rawmode = 1;