comments_open causes PHP notice in certain cases

[willnorris]

when comments_open() is called for a non-existant post (either a bad ID, or no ID passed and called from a non-single page), a PHP notice is caused. Ideally, plugins shouldn't be doing this, but a simple null check in comments_open() fixes the problem.

[willnorris]

oh, and the PHP Notice that is triggered is:

Notice: Trying to get property of non-object in .../wordpress/wp-includes/comment-template.php on line 776

[SergeyBiryukov]

pings_open() has the similar code (introduced in [6716]):
​http://core.trac.wordpress.org/browser/tags/3.5.1/wp-includes/comment-template.php#L789

Seems like the notice is appropriate in the case if a non-existent post, not sure if we should hide it. Related: ticket:17299:6.

[markoheijnen]

Maybe doing_it_wrong message?. A PHP notice isn't really telling something.

[rachelbaker]

Displaying a PHP Notice when the $post_id is invalid is expected behavior to me.