From 2cebe4395e9ed345bbbe346b91842b4c97ffcfc7 Mon Sep 17 00:00:00 2001
From: Russell Keith-Magee <russell@keith-magee.com>
Date: Mon, 12 Apr 2010 13:56:38 +0000
Subject: [PATCH] Refs #13167 -- Corrected a regression in the way non-existent
 variables are handled by {% if %} tags. Thanks to ohmi2 for pointing out the
 regression in 1.2, and Karen for the patch.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@12954 bcc190cf-cafb-0310-a4f2-bffc1f526a37
---
 django/template/defaulttags.py           | 7 ++++++-
 tests/regressiontests/templates/tests.py | 6 ++++++
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/django/template/defaulttags.py b/django/template/defaulttags.py
index 9dd5fb766f..96efa32c0f 100644
--- a/django/template/defaulttags.py
+++ b/django/template/defaulttags.py
@@ -243,7 +243,12 @@ class IfNode(Node):
             yield node
 
     def render(self, context):
-        if self.var.eval(context):
+        try:
+            var = self.var.eval(context)
+        except VariableDoesNotExist:
+            var = None
+
+        if var:
             return self.nodelist_true.render(context)
         else:
             return self.nodelist_false.render(context)
diff --git a/tests/regressiontests/templates/tests.py b/tests/regressiontests/templates/tests.py
index 93ffb4da67..372d2ab1c2 100644
--- a/tests/regressiontests/templates/tests.py
+++ b/tests/regressiontests/templates/tests.py
@@ -782,6 +782,12 @@ class Templates(unittest.TestCase):
             'if-tag-error11': ("{% if 1 == %}yes{% endif %}", {}, template.TemplateSyntaxError),
             'if-tag-error12': ("{% if a not b %}yes{% endif %}", {}, template.TemplateSyntaxError),
 
+            # Non-existent args
+            'if-tag-badarg01':("{% if x|default_if_none:y %}yes{% endif %}", {}, ''),
+            'if-tag-badarg02':("{% if x|default_if_none:y %}yes{% endif %}", {'y': 0}, ''),
+            'if-tag-badarg03':("{% if x|default_if_none:y %}yes{% endif %}", {'y': 1}, 'yes'),
+            'if-tag-badarg04':("{% if x|default_if_none:y %}yes{% else %}no{% endif %}", {}, 'no'),
+
             # Additional, more precise parsing tests are in SmartIfTests
 
             ### IFCHANGED TAG #########################################################