Only starts autosave if user is logged in

app/assets/javascripts/autosave.js

@@ -35,7 +35,10 @@ window.Autosave = (function() {
       // v-model does not update with jQuery trigger
       // https://github.com/vuejs/vue/issues/2804#issuecomment-216968137
       const event = new Event('change', { bubbles: true, cancelable: false });
-      this.field.get(0).dispatchEvent(event);
+      const field = this.field.get(0);
+      if (field) {
+        field.dispatchEvent(event);
+      }
     }
   };
 

app/assets/javascripts/notes/components/issue_comment_form.vue

@@ -184,7 +184,9 @@
         }
       },
       initAutoSave() {
-        this.autosave = new Autosave($(this.$refs.textarea), ['Note', 'Issue', this.getIssueData.id], 'issue');
+        if (this.isLoggedIn) {
+          this.autosave = new Autosave($(this.$refs.textarea), ['Note', 'Issue', this.getIssueData.id], 'issue');
+        }
       },
       initTaskList() {
         return new TaskList({