Index: src/wp-admin/includes/class-wp-ms-sites-list-table.php
===================================================================
--- src/wp-admin/includes/class-wp-ms-sites-list-table.php	(revision 48689)
+++ src/wp-admin/includes/class-wp-ms-sites-list-table.php	(working copy)
@@ -333,7 +333,8 @@
 			 */
 			do_action( 'restrict_manage_sites', $which );
 			$output = ob_get_clean();
-			if ( ! empty( $output ) ) {
+			
+			if ( $this->has_items() ) {
 				echo $output;
 				submit_button( __( 'Filter' ), '', 'filter_action', false, array( 'id' => 'site-query-submit' ) );
 			}
Index: src/wp-admin/includes/class-wp-posts-list-table.php
===================================================================
--- src/wp-admin/includes/class-wp-posts-list-table.php	(revision 48689)
+++ src/wp-admin/includes/class-wp-posts-list-table.php	(working copy)
@@ -560,7 +560,7 @@
 
 			$output = ob_get_clean();
 
-			if ( ! empty( $output ) ) {
+			if ( $this->has_items() ) {
 				echo $output;
 				submit_button( __( 'Filter' ), '', 'filter_action', false, array( 'id' => 'post-query-submit' ) );
 			}