Don't return 404 in backend

[nacin]

​http://wordpress.org/support/topic/415526

Trash all of your posts. wp-admin/edit.php sends a 404 header. In 2.9, this was a 200 header. Even though no posts are found, I don't see a reason for a 404 header in the backend.

This can cause some server issues. Someone reported some nginx issues.

Worth taking into consideration I think: http://core.trac.wordpress.org/ticket/11312#comment:14

Changed the handler for the query in post.php to use query_posts and that did the trick.

We also use wp() in wp_edit_attachments_query(), which affects upload.php.

I'm trying to think of what would change by going from wp() to query_posts() (as it has been wp() for some time), and whether it makes sense to repair our regressed logic in the handler instead. I wonder if that is as simple as an !is_admin() check.

Since the only thing that was really being used by that line was a query handling for the array $query changing it to query_posts should not affect the other parts of the system. One of the differences i have noticed is in the headers that are sent out. I could look into the wp function and get down to the line that is causing it, but query_posts works just fine. Let me know.

That patch is likely a good way to go, but I'm worried about unintended consequences. The !is_admin() check suggested by nacin seems safer for 3.0.1.

(In [15409]) Don't throw 404 in the backend. fixes #14088 for trunk.

(In [15410]) Don't throw 404 in the backend. fixes #14088 for 3.0.