Ticket #25652: 25652.2.diff

src/wp-admin/includes/update-core.php

@@ -728 +728 @@
                         // Store package-relative paths (the key) of non-writable files in the WP_Error object.
                         $error_data = version_compare( $old_wp_version, '3.7-beta2', '>' ) ? array_keys( $files_not_writable ) : '';
 
-                        if ( $files_not_writable )
-                                return new WP_Error( 'files_not_writable', __( 'Could not copy file.' ), $error_data );
+                        if ( $files_not_writable ) {
+                                $files_not_writable_error = new WP_Error( 'files_not_writable', __( 'WordPress cannot write to some files' ), $error_data );
+                                if ( defined( 'DOING_CRON' ) && DOING_CRON )
+                                        return $files_not_writable_error;
+                                else
+                                        show_message( $files_not_writable_error );
+                        }
                 }
         }