Fix #256 -- Allow exact filtering of voucher tags

src/pretix/control/forms/filter.py

@@ -1439,6 +1439,8 @@ class VoucherFilterForm(FilterForm):
             s = fdata.get('tag').strip()
             if s == '<>':
                 qs = qs.filter(Q(tag__isnull=True) | Q(tag=''))
+            elif s[0] == '"' and s[-1] == '"':
+                qs = qs.filter(tag__iexact=s[1:-1])
             else:
                 qs = qs.filter(tag__icontains=s)
 

src/pretix/control/templates/pretixcontrol/vouchers/tags.html

@@ -49,7 +49,7 @@
                         <td>
                             <strong>
                             {% if t.tag %}
-                                <a href="{% url "control:event.vouchers" organizer=request.event.organizer.slug event=request.event.slug %}?tag={{ t.tag|urlencode }}">
+                                <a href="{% url "control:event.vouchers" organizer=request.event.organizer.slug event=request.event.slug %}?tag={{ '"'|add:t.tag|add:'"'|urlencode }}">
                                     {{ t.tag }}
                                 </a>
                             {% else %}