Fixed #18916 -- Allowed non-ASCII headers.

Thanks Malcolm Tredinnick for the review.

tests/regressiontests/httpwrappers/tests.py

@@ -11,6 +11,7 @@ from django.http import (QueryDict, HttpResponse, HttpResponseRedirect,
                          SimpleCookie, BadHeaderError,
                          parse_cookie)
 from django.test import TestCase
+from django.utils.encoding import smart_str
 from django.utils import six
 from django.utils import unittest
 
@@ -228,33 +229,52 @@ class QueryDictTests(unittest.TestCase):
         self.assertEqual(copy.deepcopy(q).encoding, 'iso-8859-15')
 
 class HttpResponseTests(unittest.TestCase):
-    def test_unicode_headers(self):
+
+    def test_headers_type(self):
         r = HttpResponse()
 
-        # If we insert a unicode value it will be converted to an ascii
-        r['value'] = 'test value'
-        self.assertTrue(isinstance(r['value'], str))
+        # The following tests explicitly test types in addition to values
+        # because in Python 2 u'foo' == b'foo'.
 
-        # An error is raised when a unicode object with non-ascii is assigned.
-        self.assertRaises(UnicodeEncodeError, r.__setitem__, 'value', 't\xebst value')
+        # ASCII unicode or bytes values are converted to native strings.
+        r['key'] = 'test'
+        self.assertEqual(r['key'], str('test'))
+        self.assertIsInstance(r['key'], str)
+        r['key'] = 'test'.encode('ascii')
+        self.assertEqual(r['key'], str('test'))
+        self.assertIsInstance(r['key'], str)
 
-        # An error is raised when  a unicode object with non-ASCII format is
-        # passed as initial mimetype or content_type.
-        self.assertRaises(UnicodeEncodeError, HttpResponse,
-                content_type='t\xebst value')
+        # Latin-1 unicode or bytes values are also converted to native strings.
+        r['key'] = 'café'
+        self.assertEqual(r['key'], smart_str('café', 'latin-1'))
+        self.assertIsInstance(r['key'], str)
+        r['key'] = 'café'.encode('latin-1')
+        self.assertEqual(r['key'], smart_str('café', 'latin-1'))
+        self.assertIsInstance(r['key'], str)
 
-        # HttpResponse headers must be convertible to ASCII.
-        self.assertRaises(UnicodeEncodeError, HttpResponse,
-                content_type='t\xebst value')
+        # Other unicode values are MIME-encoded (there's no way to pass them as bytes).
+        r['key'] = '†'
+        self.assertEqual(r['key'], str('=?utf-8?b?4oCg?='))
+        self.assertIsInstance(r['key'], str)
 
-        # The response also converts unicode keys to strings.)
-        r['test'] = 'testing key'
+        # The response also converts unicode or bytes keys to strings, but requires
+        # them to contain ASCII
+        r = HttpResponse()
+        r['foo'] = 'bar'
         l = list(r.items())
-        l.sort()
-        self.assertEqual(l[1], ('test', 'testing key'))
+        self.assertEqual(l[0], ('foo', 'bar'))
+        self.assertIsInstance(l[0][0], str)
+
+        r = HttpResponse()
+        r[b'foo'] = 'bar'
+        l = list(r.items())
+        self.assertEqual(l[0], ('foo', 'bar'))
+        self.assertIsInstance(l[0][0], str)
+
+        r = HttpResponse()
+        self.assertRaises(UnicodeError, r.__setitem__, 'føø', 'bar')
+        self.assertRaises(UnicodeError, r.__setitem__, 'føø'.encode('utf-8'), 'bar')
 
-        # It will also raise errors for keys with non-ascii data.
-        self.assertRaises(UnicodeEncodeError, r.__setitem__, 't\xebst key', 'value')
 
     def test_newlines_in_headers(self):
         # Bug #10188: Do not allow newlines in headers (CR or LF)