Ticket #50686: 50686.1.patch

src/wp-admin/css/forms.css

@@ -238 +238 @@
         color: #72777c;
 }
 
-.form-invalid input,
-.form-invalid input:focus,
+.form-invalid input:not(.button):not(#custom-menu-item-name),
+.form-invalid input:not(.button):not(#custom-menu-item-name):focus,
 .form-invalid select,
 .form-invalid select:focus {
         border-color: #dc3232 !important;

src/wp-admin/nav-menus.php

@@ -961 +961 @@
                                         <div id="nav-menu-header">
                                                 <div class="major-publishing-actions wp-clearfix">
                                                         <label class="menu-name-label" for="menu-name"><?php _e( 'Menu Name' ); ?></label>
-                                                        <input name="menu-name" id="menu-name" type="text" class="menu-name regular-text menu-item-textbox" <?php echo $menu_name_val . $menu_name_aria_desc; ?> />
+                                                        <input name="menu-name" id="menu-name" type="text" class="menu-name regular-text menu-item-textbox" <?php echo $menu_name_val . $menu_name_aria_desc; ?> required="required" />
                                                         <div class="publishing-action">
                                                                 <?php submit_button( empty( $nav_menu_selected_id ) ? __( 'Create Menu' ) : __( 'Save Menu' ), 'primary large menu-save', 'save_menu', false, array( 'id' => 'save_menu_header' ) ); ?>
                                                         </div><!-- END .publishing-action -->