Consider a board where BBcode is entirely disabled by the administrator, whereas the attachment is enabled. The button "Place inline" (included in the posting_attach_body.html template) is still displayed, unlike other BBcode buttons.
The visual effect of attachment BBcode is the same as other BBcodes (no render) when BBcode is disabled. Therefore, the "Place inline" button should be hidden like other BBcode buttons.
edit: in fact, the problem is the missing S_INLINE_ATTACHMENT_OPTIONS condition for the first iteration of the input button with {L_PLACE_INLINE} value.