get_comment_class raises a PHP notice for non-registered users

[walterebert]

Calling the function get_comment_class raises a PHP notice, if a comment is from a non-registered user:

Notice: Trying to get property of non-object in /srv/www/htdocs/wp-includes/comment-template.php on line 444

I would propose to replace:

if ( $comment->user_id > 0 && $user = get_userdata( $comment->user_id ) ) {

With:

if ( ! empty( $comment->user_id ) && $user = get_userdata( $comment->user_id ) ) {

[DrewAPicture]

Hi @walterebert, welcome to Trac and thanks for the patch!

It seems like we should actually be checking if the get_comment( $comment_id ) a few lines up is returning a valid comment object. My guess is the notice you're getting is probably from an invalid comment ID being passed and core not bailing if the comment is invalid.

[DrewAPicture]

Hint: In this case we'd want to bail early and return an empty array if the comment object is invalid. It would also be nice to have test coverage for this if you'd like to try your hand at ​adding a unit test.

[walterebert]

It makes sense to me, to at least have a "comment" / "comment type" class, instead of no class at all.

I will look into writing a unit test for this.

[walterebert]

Patch + unit test

[walterebert]

My patch includes:

1. Verification if a comment is a WP_Comment object.
2. Unit test for get_comment_class.
3. Format get_comment_class according to WordPress coding standards

[dipesh.kakadiya]

Fixed PHPCS & Add more unittest for Comment object

[DrewAPicture]

Hi @dipesh.kakadiya, as a matter of course, we don't fix coding standards in unrelated code in patches. Can you remove the extra whitespace changes?

[dipesh.kakadiya]

Patch Updated - Remove whitespace

[dipesh.kakadiya]

@DrewAPicture

Hi @dipesh.kakadiya, as a matter of course, we don't fix coding standards in unrelated code in patches. Can you remove the extra whitespace changes?

Revise patch as your suggested.

[boonebgorges]

Thanks for the patches, walterebert and dipesh.kakadiya. I'm going to break the tests up a bit, and then go with the proposed fix.

[boonebgorges]

In 34453:

Add a few simple tests for get_comment_class().

Props walterebert, dipesh.kakadiya.
See #33947.

[boonebgorges]

In 34454:

Bail early when invalid ID is passed to get_comment_class().

This helps to avoid PHP notices later in the function.

Props walterebert, dipesh.kakadiya, DrewAPicture.
Fixes #33947.