Description:
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chroot() seems to be arbitrarily disabled with ZTS enabled. It seems like it is disabled because when ZTS is -usually- used it is with a sapi that requires thread safety but this isn't always the case.

AFAIK there isn't a good reason for it, I assume it's some sort of oversight - a cheap and cheerful way to achieve the above, but it doesn't account for all circumstances so you have to go hacking on the source code in about 3 different places.

It probably should be as is *except* for if CLI and possibly CGI is the SAPI.

Test script:
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<?php

var_dump(chroot("/chroot/me/here/"));


Expected result:
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bool(true)

Actual result:
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Fatal error: Call to undefined function chroot()