Fixed #18393 -- Prevented blocktrans to crash when a variable name is badly formatted.

django/templatetags/i18n.py

@@ -148,7 +148,7 @@ class BlockTranslateNode(Node):
         context.pop()
         try:
             result = result % data
-        except KeyError:
+        except (KeyError, ValueError):
             with translation.override(None):
                 result = self.render(context)
         return result

tests/regressiontests/i18n/other/locale/fr/LC_MESSAGES/django.po

@@ -17,5 +17,11 @@ msgstr ""
 "Plural-Forms: nplurals=2; plural=(n != 1)\n"
 
 #: template.html:3
+# Note: Intentional: variable name is translated.
 msgid "My name is %(person)s."
 msgstr "Mon nom est %(personne)s."
+
+#: template.html:3
+# Note: Intentional: the variable name is badly formatted (missing 's' at the end)
+msgid "My other name is %(person)s."
+msgstr "Mon autre nom est %(person)."
\ No newline at end of file

tests/regressiontests/i18n/tests.py

@@ -270,10 +270,11 @@ class TranslationTests(TestCase):
         self.assertEqual(to_language('sr_Lat'), 'sr-lat')
 
     @override_settings(LOCALE_PATHS=(os.path.join(here, 'other', 'locale'),))
-    def test_bad_placeholder(self):
+    def test_bad_placeholder_1(self):
         """
         Error in translation file should not crash template rendering
         (%(person)s is translated as %(personne)s in fr.po)
+        Refs #16516.
         """
         from django.template import Template, Context
         with translation.override('fr'):
@@ -281,6 +282,19 @@ class TranslationTests(TestCase):
             rendered = t.render(Context({'person': 'James'}))
             self.assertEqual(rendered, 'My name is James.')
 
+    @override_settings(LOCALE_PATHS=(os.path.join(here, 'other', 'locale'),))
+    def test_bad_placeholder_2(self):
+        """
+        Error in translation file should not crash template rendering
+        (%(person) misses a 's' in fr.po, causing the string formatting to fail)
+        Refs #18393.
+        """
+        from django.template import Template, Context
+        with translation.override('fr'):
+            t = Template('{% load i18n %}{% blocktrans %}My other name is {{ person }}.{% endblocktrans %}')
+            rendered = t.render(Context({'person': 'James'}))
+            self.assertEqual(rendered, 'My other name is James.')
+
 
 class FormattingTests(TestCase):