Debug strict notice in bootstrap

This issue was originally at: http://drupal.org/node/56357#comment-237166. I’m making it a separate issue so we can backport #56357 to 5.x quicker.

riccardoR discovered:

I was doing some testing on HEAD while I noticed a "Debug Strict notice" originated by this patch. Just want to tell you while this issue is still active.

Debug Strict (PHP 5): D:\var\htdocs\drupal_head\includes\bootstrap.inc line 312 - Only variables should be passed by reference

bootstrap.inc line 312 is:

$cookie_domain = '.'. array_shift(explode(':', $cookie_domain));

It seems to me that explode() actually doesn't return an array by reference.

Thanks,
Riccardo

The attached patch was rolled by Riccardo and marked RTBC by me.