[erp5_web_renderjs_ui] Do not crash if no option is selected

bt5/erp5_web_renderjs_ui/PathTemplateItem/web_page_module/rjs_gadget_html5_select_js.js

@@ -99,16 +99,20 @@
 
     .declareMethod('getContent', function getContent() {
       var result = {},
-        select = this.element.querySelector('select');
+        select = this.element.querySelector('select'),
+        selected_option;
       if (this.state.editable) {
+        selected_option = select.options[select.selectedIndex];
+        if (selected_option !== undefined) {
           result[select.getAttribute('name')] =
-          select.options[select.selectedIndex].value;
+            selected_option.value;
           // Change the value state in place
           // This will prevent the gadget to be changed if
           // its parent call render with the same value
           // (as ERP5 does in case of formulator error)
           this.state.value = result[select.getAttribute('name')];
         }
+      }
       return result;
     })
 

bt5/erp5_web_renderjs_ui/PathTemplateItem/web_page_module/rjs_gadget_html5_select_js.xml

@@ -228,7 +228,7 @@
             </item>
             <item>
                 <key> <string>serial</string> </key>
-                <value> <string>977.38881.34981.23125</string> </value>
+                <value> <string>978.42847.9438.64699</string> </value>
             </item>
             <item>
                 <key> <string>state</string> </key>
@@ -246,7 +246,7 @@
                     </tuple>
                     <state>
                       <tuple>
-                        <float>1569336908.59</float>
+                        <float>1569589427.71</float>
                         <string>UTC</string>
                       </tuple>
                     </state>