FIX: do not escape html entities in plain text templates.

dav_events/console_scripts/Resources/django.main.additional_settings.py

@@ -15,6 +15,21 @@ INSTALLED_APPS += [
     'dav_events',
 ]
 
+TEMPLATES += [
+    {
+        'NAME': 'PLAINTEXT',
+        'BACKEND': 'django.template.backends.django.DjangoTemplates',
+        'DIRS': [],
+        'APP_DIRS': True,
+        'OPTIONS': {
+            'autoescape': False,
+            'context_processors': [
+                'django.template.context_processors.debug',
+            ],
+        },
+    },
+]
+
 DATABASES['default'] = {
     'ENGINE': 'django.db.backends.sqlite3',
     'NAME': os.path.join(BASE_VAR_DIR, 'db', 'devel.sqlite3'),

dav_events/emails.py

@@ -28,7 +28,7 @@ class AbstractMail(object):
     def _get_template(self):
         if not self._template_name:
             raise ImproperlyConfigured('%s._template_name ist not set.', self.__class__.__name__)
-        return get_template(self._template_name)
+        return get_template(self._template_name, using='PLAINTEXT')
 
     def _get_context_data(self, extra_context=None):
         app_config = apps.get_containing_app_config(__package__)

dav_events/models/event.py

@@ -553,7 +553,7 @@ class Event(models.Model):
             template_name = 'default.txt'
 
         template_path = os.path.join('dav_events', 'event', template_name)
-        template = get_template(template_path)
+        template = get_template(template_path, using='PLAINTEXT')
         return template.render(self.get_template_context({'show_internal_fields': show_internal_fields}))
 
     def render_as_html(self):