help: Fix issues with new version indicator

CHANGELOG.md

@@ -9,6 +9,7 @@ All notable changes to this project will be documented in this file.
 - Added JS license web labels for LibreJS.
 - Added basic configuration form for Minetest server.
 - Added Domain Name Server (BIND) module.
+- help: Added indicator for new plinth version available.
 
 ### Changed
 - frontpage: Show app logos instead of generic icons.

plinth/modules/help/help.py

@@ -20,11 +20,12 @@ Help module for Plinth.
 """
 
 import os
+from apt.cache import Cache
 from django.http import Http404
 from django.template.response import TemplateResponse
 from django.utils.translation import ugettext as _, ugettext_lazy
 from stronghold.decorators import public
-from apt.cache import Cache
+
 from plinth import cfg, __version__
 
 
@@ -55,7 +56,7 @@ def about(request):
     context = {
         'title': _('About {box_name}').format(box_name=_(cfg.box_name)),
         'version': __version__,
-        'new_version': plinth.candidate.is_installed
+        'new_version': not plinth.candidate.is_installed
     }
     return TemplateResponse(request, 'help_about.html', context)
 

plinth/modules/help/templates/help_about.html

@@ -75,10 +75,13 @@
   <p style='margin-top:30px'>
     {% blocktrans trimmed %}
       You are running Plinth version {{ version }}.
-      {% if new_version  %} 
-        There is a new version available.
-      {% end if %}
     {% endblocktrans %}
+
+    {% if new_version %}
+      {% blocktrans trimmed %}
+        There is a new version available.
+      {% endblocktrans %}
+    {% endif %}
   </p>
 
 {% endblock %}