Related: https://bugs.php.net/bug.php?id=52982 (PHP 5.4 new session_status() function)

I believe this is intended behaviour, and the documentation is correct. 
session_start() returns true if a session is started. It returns false if a 
session fails to start. What this means is that if a session is already started, 
then it has succeeded in ensuring that a session is started, because one already 
did.

To return false when the function is called, because a session is already 
started, would likely break code that uses session_start() instead of the 
upcoming session_status() function to check whether a session is available.

The documentation is correct in saying that it only returns false if the session 
*fails* to start, in the sense that no session will be available. I've verified 
this is the behaviour in the 5.3.8 release, through the source code.

Thanks for looking into this. I'm only concerned about the docs, not changing the return value of that function. Just to have precise information about the return value at hand when reading the manual.

"This function returns TRUE if a session was successfully started or already running, otherwise FALSE."

Are you okay with such a description of the return value? This would make it more visible that the function's return value is not only related to the action it was called for, but also that it returns the previous status from the global session context before the function was called in case a session was already active.