Comments on private posts or specific edge cases can get a confusting white screen error.

[imath]

I have a plugin that uses the private status for a custom post type used in private BuddyPress groups.

When a group member tries to comment on one of the post type he's getting a white screen. I've fixed the issue on my side, problem was about caps mapping.

But still, i was pretty confused by this behavior. At first i thought it was a fatal error, but xdebug returned nothing, so i've looked in my error.log again nothing ??

Then i've found some returned WP_Error was missing data like the 403 status in wp_handle_comment_submission(). As this function was introduced in 4.4, i guess it first appeared in 4.4.

I think it could be interesting to have a screen looking like this in this kind of cases :

I suggest the attached patch.

[johnbillion]

I believe the intention if the current behaviour is to avoid exposing the existence of a private/trash/draft post for users who cannot access it.

The error text displayed for private, trash, and draft posts should be the same as that for posts which do not exist.