make sure partial has data before register

realms/static/js/main.js

@@ -75,7 +75,7 @@ var MDR = {
         if (sanitize) {
             // Causes some problems with inline styles
             html = html_sanitize(html, function(url) {
-                if(/^https?:\/\//.test(url)) {
+                if(/^(\/|https?:\/\/)/.test(url)) {
                     return url
                 }
             }, function(id){

realms/templates/wiki/edit.html

@@ -4,7 +4,13 @@
     $(function(){
       {% if partials %}
         {% for name, value in partials.items() %}
+          {% if name and value %}
+            try {
               Handlebars.registerPartial({{ name|tojson|safe }}, {{ value.data|tojson|safe }});
+            } catch(e) {
+              // no data?
+            }
+          {% endif %}
         {% endfor %}
       {% endif %}
         $("#start-togetherjs").click(function(){