Ticket #43583: is_countable-polyfill-43583.patch

src/wp-includes/compat.php

@@ -505 +505 @@
 if ( ! function_exists( 'spl_autoload_register' ) ) {
         require_once ABSPATH . WPINC . '/spl-autoload-compat.php';
 }
+
+if ( ! function_exists( 'is_countable' ) ) :
+        /**
+         * Polyfill for is_countable function added in PHP 7.3.
+         * Verify that the content of a variable is an array or an object
+         * implementing Countable
+         *
+         * @param mixed $var The value to check.
+         * @return bool Returns TRUE if var is countable, FALSE otherwise.
+         */
+        function is_countable( $var ) {
+                return ( is_array( $var ) || $var instanceof Countable );
+        }
+endif;