Patch wp_verify_nonce: fixes Advanced Custom Fields nonce bug.

gistfile1.txt

<?php
/*
Plugin Name:  Patch wp_verify_nonce
Description:  Fixes Advanced Custom Fields bug: http://support.advancedcustomfields.com/forums/topic/warnings-with-clean-install-of-acf-pro-5-0-9-and-wp-4/
Version:      1.0.0
Author:       Darin Reid
Author URI:   http://elcontraption.com/
*/

if ( !function_exists('wp_verify_nonce') ) :
/**
 * Verify that correct nonce was used with time limit.
 *
 * The user is given an amount of time to use the token, so therefore, since the
 * UID and $action remain the same, the independent variable is the time.
 *
 * @since 2.0.3
 *
 * @param string $nonce Nonce that was used in the form to verify
 * @param string|int $action Should give context to what is taking place and be the same when nonce was created.
 * @return bool Whether the nonce check passed or failed.
 */
function wp_verify_nonce($nonce, $action = -1) {

    // Fix: Typecast $nonce as a string
    $nonce = (string) $nonce;

    $user = wp_get_current_user();
    $uid = (int) $user->ID;
    if ( ! $uid ) {
        /**
         * Filter whether the user who generated the nonce is logged out.
         *
         * @since 3.5.0
         *
         * @param int    $uid    ID of the nonce-owning user.
         * @param string $action The nonce action.
         */
        $uid = apply_filters( 'nonce_user_logged_out', $uid, $action );
    }

    if ( empty( $nonce ) ) {
        return false;
    }

    $token = wp_get_session_token();
    $i = wp_nonce_tick();

    // Nonce generated 0-12 hours ago
    $expected = substr( wp_hash( $i . '|' . $action . '|' . $uid . '|' . $token, 'nonce'), -12, 10 );
    if ( hash_equals( $expected, $nonce ) ) {
        return 1;
    }

    // Nonce generated 12-24 hours ago
    $expected = substr( wp_hash( ( $i - 1 ) . '|' . $action . '|' . $uid . '|' . $token, 'nonce' ), -12, 10 );
    if ( hash_equals( $expected, $nonce ) ) {
        return 2;
    }

    // Invalid nonce
    return false;
}
endif;

Fatal error: Call to undefined function wp_get_session_token() in /home/masarche/public_html/dtr/wp-includes/pluggable.php on line 1674