Swallowing exception thrown in catch/finally block

I'm not a fan of catching and rethrowing an exception.

If you catch it, do something with it - even if it's just logging the exception.

If you can't do anything with it, don't catch it - add a throws clause to the method signature.

Catching an exception tells me that either you can deal with an exceptional situation and have a recovery plan or "the buck stops here" because an exception cannot propagate in that form any farther (e.g., no stack traces back to the user).

You can create a custom Exception type that can hold both exceptions. If you overload the ToString(), you can log both exceptions.

try
{
    transaction.Commit();
}
catch(Exception initialException)
{
    try
    {
        transaction.Rollback();
    }
    catch(Exception rollbackException)
    {
        throw new RollbackException(initialException, rollbackException);
    }

    throw;
}