Source

File: wp-includes/Requests/Cookie.php

public function path_matches($request_path) {
		if (empty($request_path)) {
			// Normalize empty path to root
			$request_path = '/';
		}

		if (!isset($this->attributes['path'])) {
			// Cookies created manually; cookies created by Requests will set
			// the path to the requested path
			return true;
		}

		$cookie_path = $this->attributes['path'];

		if ($cookie_path === $request_path) {
			// The cookie-path and the request-path are identical.
			return true;
		}

		if (strlen($request_path) > strlen($cookie_path) && substr($request_path, 0, strlen($cookie_path)) === $cookie_path) {
			if (substr($cookie_path, -1) === '/') {
				// The cookie-path is a prefix of the request-path, and the last
				// character of the cookie-path is %x2F ("/").
				return true;
			}

			if (substr($request_path, strlen($cookie_path), 1) === '/') {
				// The cookie-path is a prefix of the request-path, and the
				// first character of the request-path that is not included in
				// the cookie-path is a %x2F ("/") character.
				return true;
			}
		}

		return false;
	}