Cookie name override

gistfile1.txt

<?php

// Replace badcookiename with the cookie that you are trying to override
// Add in a custom plugin or theme's functions.php

add_action(
	'init',
	function() {
		if ( isset( $COOKIE['wp-goodcookiename'] ) ) {
			$COOKIE['badcookiename'] = $COOKIE['wp-goodcookiename'];
		}
	},
	5
);
add_action(
	'wp_loaded',
	function() {
		foreach ( headerslist() as $header ) {
			if ( stripos( $header, 'Set-Cookie: badcookiename' ) !== false ) {
				$cookieValue = substr( $header, strlen( 'Set-Cookie: ' ) );

				$cookieParts = [];
				$cookieValue = urldecode( $cookieValue );
				foreach ( explode(
					'; ',
					$cookieValue
				) as $k => $v ) {
					preg_match(
						'/^(.?)=(.?)$/i',
						trim( $v ),
						$matches
					);
							$cookieParts[ trim( $matches1 ) ] = urldecode( $matches2 );
				} setcookie(
					'wp-goodcookiename',
					$cookieParts['badcookiename'],
					strtotime( $cookieParts['expires'] ),
					$cookieParts['path'],
					$cookieParts['domain']
				);
			}
		} },
	25
);