What are the implications of using session_regenerate_id in PHP, especially in unstable network environments?

Using session_regenerate_id in PHP can help prevent session fixation attacks by changing the session ID each time a user logs in or performs a sensitive action. In unstable network environments, this function can lead to potential session inconsistencies if not handled properly, as it generates a new session ID and invalidates the old one. To mitigate this issue, you can store the old session data temporarily, regenerate the session ID, and then restore the session data.

session_start();

// Store old session data
$oldSessionData = $_SESSION;

// Regenerate session ID
session_regenerate_id();

// Restore old session data
$_SESSION = $oldSessionData;