[1.6.x] Revert "Fixed #20296 -- Allowed SafeData and EscapeData to be lazy"

This reverts commit 2ee447fb5f.

That commit introduced a regression (#21882) and didn't really
do what it was supposed to: while it did delay the evaluation
of lazy objects passed to mark_safe(), they weren't actually
marked as such so they could end up being escaped twice.

Refs #21882.

Backport of a878bf9b09 from master.

django/utils/safestring.py

@@ -4,7 +4,7 @@ without further escaping in HTML. Marking something as a "safe string" means
 that the producer of the string has already turned characters that should not
 be interpreted by the HTML engine (e.g. '<') into the appropriate entities.
 """
-from django.utils.functional import curry, Promise, allow_lazy
+from django.utils.functional import curry, Promise
 from django.utils import six
 
 class EscapeData(object):
@@ -14,13 +14,13 @@ class EscapeBytes(bytes, EscapeData):
     """
     A byte string that should be HTML-escaped when output.
     """
-    __new__ = allow_lazy(bytes.__new__, bytes)
+    pass
 
 class EscapeText(six.text_type, EscapeData):
     """
     A unicode string object that should be HTML-escaped when output.
     """
-    __new__ = allow_lazy(six.text_type.__new__, six.text_type)
+    pass
 
 if six.PY3:
     EscapeString = EscapeText
@@ -37,8 +37,6 @@ class SafeBytes(bytes, SafeData):
     A bytes subclass that has been specifically marked as "safe" (requires no
     further escaping) for HTML output purposes.
     """
-    __new__ = allow_lazy(bytes.__new__, bytes)
-
     def __add__(self, rhs):
         """
         Concatenating a safe byte string with another safe byte string or safe
@@ -71,8 +69,6 @@ class SafeText(six.text_type, SafeData):
     A unicode (Python 2) / str (Python 3) subclass that has been specifically
     marked as "safe" for HTML output purposes.
     """
-    __new__ = allow_lazy(six.text_type.__new__, six.text_type)
-
     def __add__(self, rhs):
         """
         Concatenating a safe unicode string with another safe byte string or

tests/utils_tests/test_safestring.py

@@ -4,9 +4,8 @@ from __future__ import absolute_import, unicode_literals
 from django.template import Template, Context
 from django.test import TestCase
 from django.utils.encoding import force_text, force_bytes
-from django.utils.functional import lazy, Promise
-from django.utils.html import escape, conditional_escape
-from django.utils.safestring import mark_safe, mark_for_escaping
+from django.utils.functional import lazy
+from django.utils.safestring import mark_safe, mark_for_escaping, SafeData, EscapeData
 from django.utils import six
 from django.utils import translation
 
@@ -30,8 +29,8 @@ class SafeStringTest(TestCase):
         s = lazystr('a&b')
         b = lazybytes(b'a&b')
 
-        self.assertIsInstance(mark_safe(s), Promise)
-        self.assertIsInstance(mark_safe(b), Promise)
+        self.assertIsInstance(mark_safe(s), SafeData)
+        self.assertIsInstance(mark_safe(b), SafeData)
         self.assertRenderEqual('{{ s }}', 'a&b', s=mark_safe(s))
 
     def test_mark_for_escaping(self):
@@ -43,11 +42,6 @@ class SafeStringTest(TestCase):
         s = lazystr('a&b')
         b = lazybytes(b'a&b')
 
-        self.assertIsInstance(mark_for_escaping(s), Promise)
-        self.assertIsInstance(mark_for_escaping(b), Promise)
+        self.assertIsInstance(mark_for_escaping(s), EscapeData)
+        self.assertIsInstance(mark_for_escaping(b), EscapeData)
         self.assertRenderEqual('{% autoescape off %}{{ s }}{% endautoescape %}', 'a&b', s=mark_for_escaping(s))
-
-    def test_regression_20296(self):
-        s = mark_safe(translation.ugettext_lazy("username"))
-        with translation.override('fr'):
-            self.assertRenderEqual('{{ s }}', "nom d'utilisateur", s=s)