Issue #3439345: Test for redirection after login
Closes #3439345
This merge request includes the following changes:
- Fix a bug that makes previous test failed.
- Add a new member function called 'isTrustedUrl()' to check whether an URL is trusted.
- Use the new function to check the redirect URL before putting it into the cookie and redirecting.
- A new PHPUnit test to make sure the redirection is safe.
Edited by Mingsong