Unexpected flashdata behavior

[eluser]Jeka[/eluser]
[quote author="mddd" date="1276808602"]You're welcome. HTTP headers are often a bit wacky.

About the IF condition: check what your get_user() method is returning. Maybe in some circumstance it is returning something that does not evaluate to 'false'?[/quote]

Under which conditions do you think the statement would set the flash variable but not redirect?

I just tried if (false) and you're right, it works okay then.

What's the best way to test for this in your opinion?