add "any" nonstop zone filter

nonstop/forms.py

@@ -11,7 +11,9 @@ def get_optional_nonstop_zones():
     return [('', '')] + get_nonstop_zones()
 
 def get_search_nonstop_zones():
-    return [('', 'All'), ('', '--------------')] + get_nonstop_zones() + [('', '--------------'), ('none', 'None')]
+    return [('', 'All'),
+            ('any', _('Any')),
+            ('', '--------------')] + get_nonstop_zones() + [('', '--------------'), ('none', 'None')]
 
 class UploadTracksForm(forms.Form):
     tracks = forms.FileField(widget=forms.ClearableFileInput(

nonstop/views.py

@@ -262,6 +262,8 @@ class SearchView(TemplateView):
             from emissions.models import Nonstop
             if zone == 'none':
                 queryset = queryset.filter(nonstop_zones=None)
+            elif zone == 'any':
+                queryset = queryset.filter(nonstop_zones__isnull=False).distinct()
             else:
                 queryset = queryset.filter(nonstop_zones=zone)