Ticket #39459: 39459.diff

wp-admin/admin.php

@@ -32 +32 @@
 
 nocache_headers();
 
-if ( get_option('db_upgraded') ) {
+if ( ! wp_doing_ajax() && get_option( 'db_upgraded' ) ) {
         flush_rewrite_rules();
         update_option( 'db_upgraded',  false );
 
@@ -42 +42 @@
          * @since 2.8.0
          */
         do_action( 'after_db_upgrade' );
-} elseif ( get_option('db_version') != $wp_db_version && empty($_POST) ) {
+} elseif ( ! wp_doing_ajax() &&
+        get_option( 'db_version' ) != $wp_db_version &&
+        empty($_POST)
+) {
         if ( !is_multisite() ) {
                 wp_redirect( admin_url( 'upgrade.php?_wp_http_referer=' . urlencode( wp_unslash( $_SERVER['REQUEST_URI'] ) ) ) );
                 exit;