Description:
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The session_start() documentation does not state that it sets the Cache-Control, Expires, and Pragma headers.

While this is probably proper behavior for 99% of the sites out there, the documentation should at least notify the programmer that these headers are being sent.

Source URL: http://us2.php.net/function.session-start


Reproduce code:
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NA

Expected result:
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session_start() will send the following http headers:

Expires: Thu, 19 Nov 1981 08:52:00 GMT
Cache-Control: no-store, no-cache, must-revalidate, post-check=0, pre-check=0
Pragma: no-cache

These headers are set to insure that information generated for a unique user will not be cached by a proxy or the user's browser.

The usage of session_start() implies user customized data.

See: 

* http://us2.php.net/manual/en/function.session-cache-limiter.php 
* http://us2.php.net/manual/en/function.session-cache-expire.php

For further info on adjusting these headers.