diff --git a/django/template/base.py b/django/template/base.py index 8a9099baa5..4ac20b13e1 100644 --- a/django/template/base.py +++ b/django/template/base.py @@ -19,7 +19,7 @@ from django.utils.translation import ugettext_lazy, pgettext_lazy from django.utils.safestring import (SafeData, EscapeData, mark_safe, mark_for_escaping) from django.utils.formats import localize -from django.utils.html import escape +from django.utils.html import conditional_escape from django.utils.module_loading import module_has_submodule from django.utils import six from django.utils.timezone import template_localtime @@ -887,7 +887,7 @@ def render_value_in_context(value, context): value = force_text(value) if ((context.autoescape and not isinstance(value, SafeData)) or isinstance(value, EscapeData)): - return escape(value) + return conditional_escape(value) else: return value diff --git a/django/template/debug.py b/django/template/debug.py index cf9c2a59fc..465d7ff926 100644 --- a/django/template/debug.py +++ b/django/template/debug.py @@ -1,6 +1,6 @@ from django.template.base import Lexer, Parser, tag_re, NodeList, VariableNode, TemplateSyntaxError from django.utils.encoding import force_text -from django.utils.html import escape +from django.utils.html import conditional_escape from django.utils.safestring import SafeData, EscapeData from django.utils.formats import localize from django.utils.timezone import template_localtime @@ -98,6 +98,6 @@ class DebugVariableNode(VariableNode): e.django_template_source = self.source raise if (context.autoescape and not isinstance(output, SafeData)) or isinstance(output, EscapeData): - return escape(output) + return conditional_escape(output) else: return output diff --git a/django/utils/html.py b/django/utils/html.py index 3c03210c11..a596662d22 100644 --- a/django/utils/html.py +++ b/django/utils/html.py @@ -44,6 +44,10 @@ def escape(text): """ Returns the given text with ampersands, quotes and angle brackets encoded for use in HTML. + + This function always escapes its input, even if it's already escaped and + marked as such. This may result in double-escaping. If this is a concern, + use conditional_escape() instead. """ return mark_safe(force_text(text).replace('&', '&').replace('<', '<') .replace('>', '>').replace('"', '"').replace("'", ''')) @@ -76,6 +80,9 @@ escapejs = allow_lazy(escapejs, six.text_type, SafeText) def conditional_escape(text): """ Similar to escape(), except that it doesn't operate on pre-escaped strings. + + This function relies on the __html__ convention used both by Django's + SafeData class and by third-party libraries like markupsafe. """ if hasattr(text, '__html__'): return text.__html__() diff --git a/django/utils/safestring.py b/django/utils/safestring.py index 50b0c03686..ab4d8149c9 100644 --- a/django/utils/safestring.py +++ b/django/utils/safestring.py @@ -36,9 +36,9 @@ else: class SafeData(object): def __html__(self): """ - Returns the html representation of a string. + Returns the html representation of a string for interoperability. - Allows interoperability with other template engines. + This allows other template engines to understand Django's SafeData. """ return self @@ -121,7 +121,7 @@ def mark_safe(s): Can be called multiple times on a single string. """ - if isinstance(s, SafeData): + if hasattr(s, '__html__'): return s if isinstance(s, bytes) or (isinstance(s, Promise) and s._delegate_bytes): return SafeBytes(s) @@ -138,7 +138,7 @@ def mark_for_escaping(s): Can be called multiple times on a single string (the resulting escaping is only applied once). """ - if isinstance(s, (SafeData, EscapeData)): + if hasattr(s, '__html__') or isinstance(s, EscapeData): return s if isinstance(s, bytes) or (isinstance(s, Promise) and s._delegate_bytes): return EscapeBytes(s) diff --git a/tests/utils_tests/test_safestring.py b/tests/utils_tests/test_safestring.py index 053d9f42fa..e23851815b 100644 --- a/tests/utils_tests/test_safestring.py +++ b/tests/utils_tests/test_safestring.py @@ -13,6 +13,13 @@ lazystr = lazy(force_text, six.text_type) lazybytes = lazy(force_bytes, bytes) +class customescape(six.text_type): + def __html__(self): + # implement specific and obviously wrong escaping + # in order to be able to tell for sure when it runs + return self.replace('<', '<<').replace('>', '>>') + + class SafeStringTest(TestCase): def assertRenderEqual(self, tpl, expected, **context): context = Context(context) @@ -25,6 +32,14 @@ class SafeStringTest(TestCase): self.assertRenderEqual('{{ s }}', 'a&b', s=s) self.assertRenderEqual('{{ s|force_escape }}', 'a&b', s=s) + def test_mark_safe_object_implementing_dunder_html(self): + e = customescape('') + s = mark_safe(e) + self.assertIs(s, e) + + self.assertRenderEqual('{{ s }}', '<>', s=s) + self.assertRenderEqual('{{ s|force_escape }}', '<a&b>', s=s) + def test_mark_safe_lazy(self): s = lazystr('a&b') b = lazybytes(b'a&b') @@ -42,11 +57,25 @@ class SafeStringTest(TestCase): self.assertRenderEqual('{{ s }}', '', s=s) + def test_mark_safe_result_implements_dunder_html(self): + self.assertEqual(mark_safe('a&b').__html__(), 'a&b') + + def test_mark_safe_lazy_result_implements_dunder_html(self): + self.assertEqual(mark_safe(lazystr('a&b')).__html__(), 'a&b') + def test_mark_for_escaping(self): s = mark_for_escaping('a&b') self.assertRenderEqual('{{ s }}', 'a&b', s=s) self.assertRenderEqual('{{ s }}', 'a&b', s=mark_for_escaping(s)) + def test_mark_for_escaping_object_implementing_dunder_html(self): + e = customescape('') + s = mark_for_escaping(e) + self.assertIs(s, e) + + self.assertRenderEqual('{{ s }}', '<>', s=s) + self.assertRenderEqual('{{ s|force_escape }}', '<a&b>', s=s) + def test_mark_for_escaping_lazy(self): s = lazystr('a&b') b = lazybytes(b'a&b') @@ -55,10 +84,6 @@ class SafeStringTest(TestCase): self.assertIsInstance(mark_for_escaping(b), EscapeData) self.assertRenderEqual('{% autoescape off %}{{ s }}{% endautoescape %}', 'a&b', s=mark_for_escaping(s)) - def test_html(self): - s = '

interop

' - self.assertEqual(s, mark_safe(s).__html__()) - def test_mark_for_escaping_object_implementing_dunder_str(self): class Obj(object): def __str__(self):