Ensure TemplateResponses returned by views are rendered within the co…

…ntext of translation.override()

wagtail/admin/decorators.py

@@ -2,8 +2,7 @@
 from django.core.exceptions import PermissionDenied
 from django.urls import reverse
 from django.utils.timezone import activate as activate_tz
-from django.utils.translation import activate as activate_lang
-from django.utils.translation import ugettext as _
+from django.utils.translation import override, ugettext as _
 
 from wagtail.admin import messages
 from wagtail.utils import l18n
@@ -25,13 +24,19 @@ def decorated_view(request, *args, **kwargs):
             return reject_request(request)
 
         if user.has_perms(['wagtailadmin.access_admin']):
+            preferred_language = None
             if hasattr(user, 'wagtail_userprofile'):
-                language = user.wagtail_userprofile.get_preferred_language()
-                l18n.set_language(language)
-                activate_lang(language)
+                preferred_language = user.wagtail_userprofile.get_preferred_language()
+                l18n.set_language(preferred_language)
                 time_zone = user.wagtail_userprofile.get_current_time_zone()
                 activate_tz(time_zone)
-            return view_func(request, *args, **kwargs)
+            with override(preferred_language):
+                response = view_func(request, *args, **kwargs)
+                if hasattr(response, 'render'):
+                    return response.render()
+                return response
+
+
 
         if not request.is_ajax():
             messages.error(request, _('You do not have permission to access the admin'))