[FIX] web: don't display view metadata for new record

Close #11584

addons/web/static/src/js/widgets/debug_manager.js

@@ -85,6 +85,10 @@ if (core.debug) {
         },
         get_metadata: function() {
             var ds = this.dataset;
+            if (!this.view.get_selected_ids().length) {
+                console.warn(_t("No metadata available"));
+                return
+            }
             ds.call('get_metadata', [this.view.get_selected_ids()]).done(function(result) {
                 new Dialog(this, {
                     title: _.str.sprintf(_t("Metadata (%s)"), ds.model),

addons/web/static/src/xml/base.xml

@@ -204,7 +204,9 @@
 </t>
 <t t-name="WebClient.DebugDropdown">
     <t t-if="active_view.type === 'form'">
-        <li class="oe_metadata"><a href="#" data-action="get_metadata">View Metadata</a></li>
+        <t t-if="active_view.controller.get_selected_ids().length == 1">
+            <li class="oe_metadata"><a href="#" data-action="get_metadata">View Metadata</a></li>
+        </t>
         <li class="oe_layout"><a href="#" data-action="toggle_layout_outline">Toggle Form Layout Outline</a></li>
         <li class="oe_defaults"><a href="#" data-action="set_defaults">Set Defaults</a></li>
     </t>