BUG: formhandler clear all removes all params

src/formhandler.template.html

@@ -327,7 +327,7 @@ Each template receives these variables:
       _.each(args[key], function(col_name) {
         var update = {}
         update[key] = col_name
-        qparts.update(update) %>
+        qparts.update(update, 'add') %>
         <a href="?<%- key %>=<%- col_name %>" data-mode="del" class="badge badge-pill badge-dark urlfilter" title="Clear <%- key %> filter">
           <%- key %> = <%- col_name %>
         </a>

test/test-formhandler.html

@@ -65,6 +65,7 @@
   <div class="custom_buttons4" data-src="/formhandler-data"></div>
   <div class="custom_buttons5" data-src="/formhandler-data"></div>
 
+  <div class="fh18" data-src="/formhandler-data"></div>
   <div class="fh17" data-src="/formhandler-data"></div>
   <div class="fh15" data-src="/formhandler-data"></div>
   <div class="fh16" data-src="/formhandler-data"></div>
@@ -538,6 +539,19 @@
           t.end()
         })
     })
+    tape('$().formhandler() test clear all for multiple filters', function (t) {
+      window.history.pushState({}, '', '#')
+      window.history.pushState({}, '', '#' + g1.url.parse().update({ 'Continent': ['Asia', 'Europe'], _limit: 5 }).toString())
+      $('.fh18').formhandler()
+        .on('load', function () {
+          var filter_badges = $('body > div.fh18 > div.position-relative > div.formhandler > div.formhandler-table-header > div.d-flex > div.filters > div > a')
+          t.equal(filter_badges[0].text.trim(), 'Continent = Asia')
+          t.equal(filter_badges[1].text.trim(), 'Continent = Europe')
+          t.equal(filter_badges[2].getAttribute('href'), '?Continent=Asia&Continent=Europe')
+          window.history.pushState({}, '', '#')
+          t.end()
+        })
+    })
     // tape('$().formhandler() add new rows', function (t) {
     //   $('.fh_add1')
     //     .formhandler({