templatetag "blocktrans" ignores the TEMPLATE_STRING_IF_INVALID setting

[Natalia Bidart]

If I define the setting TEMPLATE_STRING_IF_INVALID to something other than the empty string, for example:

TEMPLATE_STRING_IF_INVALID = 'INVALID'

when I have a template that uses the templatetag blocktrans, all those variables not defined in any context (neither local nor global context) are not shown as INVALID but they are rendered as the empty string instead.

You can reproduce this by:

• define the setting to be:

TEMPLATE_STRING_IF_INVALID = 'INVALID'

• create a dummy template foo.txt:

{% load i18n %}

{% blocktrans %}Hello {{ thing }}!

Django {{ action }} big time!
{% endblocktrans %}

• render the template with an incomplete context:

>>> from django.template.loader import render_to_string
>>> print render_to_string('foo.txt', {'thing': 'world'})

Hello world!

Django  big time!

• then, remove the blocktrans tags, and re-render, you will get instead:

>>> print render_to_string('foo.txt', {'thing': 'world'})

Hello world!

Django INVALID big time!

I would expect the same behaviour with or without the use of blocktrans.

[Natalia Bidart]

A simple solution would be to apply something like this (if approved I can propose a proper patch with tests):

django/templatetags/i18n.py

@@ -143 +143 @@
                 result = translation.pgettext(message_context, singular)
             else:
                 result = translation.ugettext(singular)
-        data = dict([(v, render_value_in_context(context.get(v, ''), context)) for v in vars])
+        from django.conf import settings
+        data = dict([(v, render_value_in_context(context.get(v, settings.TEMPLATE_STRING_IF_INVALID), context)) for v in vars])
         context.pop()
         try:
             result = result % data

[matiasb]

Proposed fix, pull request: ​https://github.com/django/django/pull/865
(all tests passing using SQLite).

[Ramiro Morales <cramm0@…>]

In 804366327d728d23a9f7a25ff77a6eed3c9f9323:

Fixed #19915 - Made blocktrans tag honor TEMPLATE_STRING_IF_INVALID.

Thanks Natalia Bidart for the report and Matías Bordese for the fix.

[Claude Paroz <claude@…>]

In 02add43568b694ef25afeae474b5b1da883826c6:

Fixed #21417 -- Expanded TEMPLATE_STRING_IF_INVALID in blocktrans

Thanks keturn for the reporti, Chris Medrela for details and
Tim Graham for the review.
Refs #19915.