[renderjs_ui] MultiListField does not crash when only one item is selected

/reviewed-on nexedi/erp5!448

bt5/erp5_web_renderjs_ui/PathTemplateItem/web_page_module/rjs_gadget_erp5_multilistfield_js.js

@@ -3,6 +3,13 @@
 (function (window, rJS, document, RSVP) {
   'use strict';
 
+  /* Make sure that returned object is an Array instance. */
+  function ensureArray(obj) {
+    if (!obj) {return []; }
+    if (Array.isArray(obj)) {return obj; }
+    return [obj];
+  }
+
   function appendListField(gadget, value, item_list) {
     var div = document.createElement('div');
     gadget.element.appendChild(div);
@@ -32,8 +39,9 @@
       var field_json = options.field_json || {},
         item_list = field_json.items,
         state_dict = {
-          value_list: JSON.stringify(field_json.value ||
-                                     field_json.default || []),
+          value_list: JSON.stringify(
+            ensureArray(field_json.value || field_json.default)
+          ),
           editable: field_json.editable,
           required: field_json.required,
           name: field_json.key,

bt5/erp5_web_renderjs_ui/PathTemplateItem/web_page_module/rjs_gadget_erp5_multilistfield_js.xml

@@ -230,7 +230,7 @@
             </item>
             <item>
                 <key> <string>serial</string> </key>
-                <value> <string>955.51162.4768.35123</string> </value>
+                <value> <string>962.38785.31645.18483</string> </value>
             </item>
             <item>
                 <key> <string>state</string> </key>
@@ -248,7 +248,7 @@
                     </tuple>
                     <state>
                       <tuple>
-                        <float>1482843497.05</float>
+                        <float>1507301921.45</float>
                         <string>UTC</string>
                       </tuple>
                     </state>