$page is always set

[hakre]

in wp-app.php

fix

There's not really any way to guarantee that $page isn't passed as null when calling wp_atom_server::get_feed(). While I can't immediately see any location where it's called that won't result in $page not being set to null, this single extra check is only run once on any single request, so it's not a performance issue. I'm sure the check was added in there for a good reason originally, so it's really not worth removing it now and possibly breaking something without realizing it.

I do know that it is possible that a plugin is calling wp_atom_server::get_feed() with page passed as null, and that if a plugin wanted to specify a custom post type while relying on the default page specified in WP core, they would absolutely be required to pass null.