Don't crash if there is a key error in a template. Bug 556814

examples/jingo-project/locale/xx/LC_MESSAGES/messages.po

@@ -0,0 +1,4 @@
+#, python-format
+msgid "Broken %(string)s"
+msgstr "Broken %(fuuu)s"
+

examples/jingo-project/settings.py

@@ -1 +1,7 @@
+import os
+
+# Make filepaths relative to settings.
+ROOT = os.path.dirname(os.path.abspath(__file__))
+path = lambda *a: os.path.join(ROOT, *a)
+
 JINJA_CONFIG = {}

fabfile.py

@@ -26,11 +26,12 @@ def doc(kind='html'):
     with cd('docs'):
         local('make clean %s' % kind)
 
+def shell():
+    local('django-admin.py shell')
 
 def test():
     local('nosetests')
 
-
 def updoc():
     doc('dirhtml')
     rsync_project('p/%s' % NAME, 'docs/_build/dirhtml/', delete=True)

jingo/__init__.py

@@ -4,8 +4,10 @@ import functools
 from django import http
 from django.conf import settings
 from django.template.context import get_standard_processors
+from django.utils.translation import trans_real
 
 import jinja2
+import tower
 
 VERSION = (0, 3)
 __version__ = '.'.join(map(str, VERSION))
@@ -74,7 +76,14 @@ def render_to_string(request, template, context=None):
     # If it's not a Template, it must be a path to be loaded.
     if not isinstance(template, jinja2.environment.Template):
         template = env.get_template(template)
-    return template.render(**context)
+    try:
+        ret = template.render(**context)
+    except KeyError:
+        _lang = trans_real.get_language()
+        tower.deactivate_all()
+        ret = template.render(**context)
+        tower.activate(_lang)
+    return ret
 
 
 def load_helpers():

jingo/tests/test_views.py

@@ -1,6 +1,11 @@
-from mock import patch, sentinel
+from mock import Mock, patch, sentinel
 
+from nose.tools import eq_
+from test_helpers import render
 import jingo.views
+from jingo import get_env
+import jinja2
+import tower
 
 
 @patch('jingo.render')
@@ -8,3 +13,15 @@ def test_direct_to_template(mock_render):
     request = sentinel.request
     jingo.views.direct_to_template(request, 'base.html', x=1)
     mock_render.assert_called_with(request, 'base.html', {'x': 1})
+
+
+def test_template_substitution_crash():
+    tower.activate('xx')
+
+    env = get_env()
+
+    # The localized string has the wrong variable name in it
+    s = '{% trans string="heart" %}Broken {{ string }}{% endtrans %}'
+    template = env.from_string(s)
+    rendered = jingo.render_to_string(Mock(), template, {})
+    eq_(rendered, 'Broken heart')

requirements.txt

@@ -4,4 +4,5 @@ jinja2
 nose
 mock
 -e svn+http://code.djangoproject.com/svn/django/trunk@12335#egg=Django
+-e git://github.com/clouserw/tower.git#egg=tower
 fabric