Bug in wp_attachment_is_image

[odedstr2]

On wp-includes/post.php
Line 4031:

if ( !$file = get_attached_file( $post->ID ) )

SHOULD BE:

if ( !$file = get_attached_file( $post_id ) )

By the way, the variable name $post_id is very bad, as this is the Attachment ID, not the Post ID. Probably this variable naming mistake resulted in this bug.

[SergeyBiryukov]

$post->ID is actually the same value, since $post is set earlier in line 4028:
​http://core.trac.wordpress.org/browser/tags/3.4.2/wp-includes/post.php#L4028

It could be $post_id as well, but there's no bug here.