From 0928fa5566bac9404a5a0d1810c2c00ffa81c59f Mon Sep 17 00:00:00 2001
From: Malcolm Tredinnick <malcolm.tredinnick@gmail.com>
Date: Sat, 17 Nov 2007 12:11:26 +0000
Subject: [PATCH] Fixed #5945 -- Treat string literals in template filter
 arguments as safe strings for auto-escaping purposes.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@6680 bcc190cf-cafb-0310-a4f2-bffc1f526a37
---
 django/template/__init__.py                |  4 ++--
 docs/templates.txt                         | 26 ++++++++++++++++++++++
 tests/regressiontests/templates/filters.py |  9 ++++----
 tests/regressiontests/templates/tests.py   | 13 ++++++-----
 4 files changed, 39 insertions(+), 13 deletions(-)

diff --git a/django/template/__init__.py b/django/template/__init__.py
index edc2150af0..761c08d6c9 100644
--- a/django/template/__init__.py
+++ b/django/template/__init__.py
@@ -594,7 +594,7 @@ class FilterExpression(object):
             arg_vals = []
             for lookup, arg in args:
                 if not lookup:
-                    arg_vals.append(arg)
+                    arg_vals.append(mark_safe(arg))
                 else:
                     arg_vals.append(arg.resolve(context))
             if getattr(func, 'needs_autoescape', False):
@@ -707,7 +707,7 @@ class Variable(object):
             # If it's wrapped with quotes (single or double), then
             # we're also dealing with a literal.
             if var[0] in "\"'" and var[0] == var[-1]:
-                self.literal = var[1:-1]
+                self.literal = mark_safe(var[1:-1])
             else:
                 # Otherwise we'll set self.lookups so that resolve() knows we're
                 # dealing with a bonafide variable
diff --git a/docs/templates.txt b/docs/templates.txt
index 020586159c..07258bb46a 100644
--- a/docs/templates.txt
+++ b/docs/templates.txt
@@ -401,6 +401,32 @@ auto-escaping is on, these extra filters won't change the output -- any
 variables that use the ``escape`` filter do not have further automatic
 escaping applied to them.
 
+String literals and automatic escaping
+--------------------------------------
+
+Sometimes you will pass a string literal as an argument to a filter. For
+example::
+
+    {{ data|default:"This is a string literal." }}
+
+All string literals are inserted **without** any automatic escaping into the
+template, if they are used (it's as if they were all passed through the
+``safe`` filter). The reasoning behind this is that the template author is in
+control of what goes into the string literal, so they can make sure the text
+is correctly escaped when the template is written.
+
+This means you would write ::
+
+    {{ data|default:"3 &gt; 2" }}
+
+...rather than ::
+
+    {{ data|default:"3 > 2" }}  <-- Bad! Don't do this.
+
+This doesn't affect what happens to data coming from the variable itself.
+The variable's contents are still automatically escaped, if necessary, since
+they're beyond the control of the template author.
+
 Using the built-in reference
 ============================
 
diff --git a/tests/regressiontests/templates/filters.py b/tests/regressiontests/templates/filters.py
index 5d7129480c..00dfbe3c35 100644
--- a/tests/regressiontests/templates/filters.py
+++ b/tests/regressiontests/templates/filters.py
@@ -177,18 +177,17 @@ def get_filter_tests():
         'filter-unordered_list04': ('{% autoescape off %}{{ a|unordered_list }}{% endautoescape %}', {"a": ["x>", [[mark_safe("<y"), []]]]}, "\t<li>x>\n\t<ul>\n\t\t<li><y</li>\n\t</ul>\n\t</li>"),
         'filter-unordered_list05': ('{% autoescape off %}{{ a|unordered_list }}{% endautoescape %}', {"a": ["x>", [["<y", []]]]}, "\t<li>x>\n\t<ul>\n\t\t<li><y</li>\n\t</ul>\n\t</li>"),
 
-        # If the input to "default" filter is marked as safe, then so is the
-        # output. However, if the default arg is used, auto-escaping kicks in
-        # (if enabled), because we cannot mark the default as safe.
+        # Literal string arguments to the default filter are always treated as
+        # safe strings, regardless of the auto-escaping state.
         #
         # Note: we have to use {"a": ""} here, otherwise the invalid template
         # variable string interferes with the test result.
-        'filter-default01': ('{{ a|default:"x<" }}', {"a": ""}, "x&lt;"),
+        'filter-default01': ('{{ a|default:"x<" }}', {"a": ""}, "x<"),
         'filter-default02': ('{% autoescape off %}{{ a|default:"x<" }}{% endautoescape %}', {"a": ""}, "x<"),
         'filter-default03': ('{{ a|default:"x<" }}', {"a": mark_safe("x>")}, "x>"),
         'filter-default04': ('{% autoescape off %}{{ a|default:"x<" }}{% endautoescape %}', {"a": mark_safe("x>")}, "x>"),
 
-        'filter-default_if_none01': ('{{ a|default:"x<" }}', {"a": None}, "x&lt;"),
+        'filter-default_if_none01': ('{{ a|default:"x<" }}', {"a": None}, "x<"),
         'filter-default_if_none02': ('{% autoescape off %}{{ a|default:"x<" }}{% endautoescape %}', {"a": None}, "x<"),
 
         'filter-phone2numeric01': ('{{ a|phone2numeric }} {{ b|phone2numeric }}', {"a": "<1-800-call-me>", "b": mark_safe("<1-800-call-me>") }, "&lt;1-800-2255-63&gt; <1-800-2255-63>"),
diff --git a/tests/regressiontests/templates/tests.py b/tests/regressiontests/templates/tests.py
index 74e6fd5cef..7eb4ae06b0 100644
--- a/tests/regressiontests/templates/tests.py
+++ b/tests/regressiontests/templates/tests.py
@@ -318,9 +318,9 @@ class Templates(unittest.TestCase):
             # Chained filters, with an argument to the first one
             'filter-syntax09': ('{{ var|removetags:"b i"|upper|lower }}', {"var": "<b><i>Yes</i></b>"}, "yes"),
 
-            # Escaped string as argument
+            # Literal string as argument is always "safe" from auto-escaping..
             'filter-syntax10': (r'{{ var|default_if_none:" endquote\" hah" }}',
-                    {"var": None}, ' endquote&quot; hah'),
+                    {"var": None}, ' endquote" hah'),
 
             # Variable as argument
             'filter-syntax11': (r'{{ var|default_if_none:var2 }}', {"var": None, "var2": "happy"}, 'happy'),
@@ -735,9 +735,10 @@ class Templates(unittest.TestCase):
             'i18n12': ('{% load i18n %}{% get_available_languages as langs %}{% for lang in langs %}{% ifequal lang.0 "de" %}{{ lang.0 }}{% endifequal %}{% endfor %}', {}, 'de'),
 
             # translation of constant strings
-            'i18n13': ('{{ _("Page not found") }}', {'LANGUAGE_CODE': 'de'}, 'Seite nicht gefunden'),
+            'i18n13': ('{{ _("Password") }}', {'LANGUAGE_CODE': 'de'}, 'Passwort'),
             'i18n14': ('{% cycle "foo" _("Password") _(\'Password\') as c %} {% cycle c %} {% cycle c %}', {'LANGUAGE_CODE': 'de'}, 'foo Passwort Passwort'),
             'i18n15': ('{{ absent|default:_("Password") }}', {'LANGUAGE_CODE': 'de', 'absent': ""}, 'Passwort'),
+            'i18n16': ('{{ _("<") }}', {'LANGUAGE_CODE': 'de'}, '<'),
 
             ### HANDLING OF TEMPLATE_STRING_IF_INVALID ###################################
 
@@ -885,9 +886,9 @@ class Templates(unittest.TestCase):
             'autoescape-tag06': ("{{ first }}", {"first": mark_safe("<b>first</b>")}, "<b>first</b>"),
             'autoescape-tag07': ("{% autoescape on %}{{ first }}{% endautoescape %}", {"first": mark_safe(u"<b>Apple</b>")}, u"<b>Apple</b>"),
 
-            # String arguments to filters, if used in the result, are escaped,
-            # too.
-            'basic-syntax08': (r'{% autoescape on %}{{ var|default_if_none:" endquote\" hah" }}{% endautoescape %}', {"var": None}, ' endquote&quot; hah'),
+            # Literal string arguments to filters, if used in the result, are
+            # safe.
+            'basic-syntax08': (r'{% autoescape on %}{{ var|default_if_none:" endquote\" hah" }}{% endautoescape %}', {"var": None}, ' endquote" hah'),
 
             # The "safe" and "escape" filters cannot work due to internal
             # implementation details (fortunately, the (no)autoescape block