Redirect to canonical URL if URL has 'preview' parameter with any nonempty value and user not log in

[egorpromo]

if any URL has nonempty GET-parameter 'preview' that there is noredirection to canonical URL.
If we have ​http://example.com?p={post_id}&post_type={post_slug}&preview=true there is no redirection to correct URL like ​http://example.com?{post_type}={post_slug} or like ​http://example.com/{post_type}/{post_slug} (if site has permalinks). This is bad for SEO and bad user experience. If user not log in there must be redirecttion.

[SergeyBiryukov]

Related: #20496

[joostdevalk]

I think that if the patch currently attached to #20496 goes in, the most important bit for this would be fixed, and we'd probably resolve the remainder as won't fix since we don't really redirect out parameters *anywhere*.... Agreed?

[egorpromo]

Replying to joostdevalk:

I think that if the patch currently attached to #20496 goes in, the most important bit for this would be fixed, and we'd probably resolve the remainder as won't fix since we don't really redirect out parameters *anywhere*.... Agreed?

If you are asking me that I could say I just draw attention to the problem. It could be good if wordpress will have strong canonical component.

[wonderboymusic]

#20496 is in, wontfix as per @joostdevalk in comment:2