Strange pagination issue

[sachit.tandukar]

Hi,

I am facing strange pagination issue in WordPress. I could replicate it on other major WordPress websites as well apart from the one I am working on.

If you check this website: ​https://highlandexpeditions.com/blog/, everything works fine. Pagination works fine too.

However, if you visit ​https://highlandexpeditions.com/blog/2/, you will get the same page as ​https://highlandexpeditions.com/blog/. But the pagination links are ruined. You will have pagination links like (​https://highlandexpeditions.com/blog/2/page/2/, ​https://highlandexpeditions.com/blog/2/page/3/) which goes to 404 page.

I think WordPress should show 404 for ​https://highlandexpeditions.com/blog/2/ rather than showing ​https://highlandexpeditions.com/blog/.

I don't think it has anything to do with themes or plugin. Because another popular website like ​https://www.wpbeginner.com/blog/ has the same issue. If you visit this URL (​https://www.wpbeginner.com/blog/2/), you will find its pagination URL is wrong. I am able to replicate it on other websites as well.

Thanks.

[jeremyfelt]

Hi @sachittandukar, thanks for opening a ticket.

This seems similar to #28081, but likely different enough to have its own ticket. That deals with the paged query variable and this deals with page. This was partially fixed in #11694, which introduced the current page checking in [34492].

There are (at least) two ways in which this presents itself:

First: when a request is made to any is_singular() post/page with /2/ appended to the URL, WordPress checks for an instance of <!--nextpage--> in the content. If it exists, and it matches the page number, $success is set to true and the page is loaded. If the next page marker does not exist, there is no current check that flags the content for 404 if a page number is part of the URL. For that, we could do something like 45337.diff​ to return a 404 if content is not paged.

Second: (highlighted in the ticket description), when a page is set as the page_for_posts, is_singular() is false and the logic handling <!--nextpage--> is skipped entirely. Earlier in the process, the query object was populated with posts, so as far as handle_404() is concerned, is_home() is true and the page can be loaded as is. The fix for this seems a little more complicated and _could_ be handled earlier in the process.

[SergeyBiryukov]

#48972 was marked as a duplicate.

[SergeyBiryukov]

#44587 was marked as a duplicate.

[SergeyBiryukov]

In 47727:

Canonical: Redirect paged requests for non-paginated posts to the post permalink.

This avoids displaying duplicate content of the same post under different URLs and ensures the canonical URL is correct.

Previously, requests for invalid page numbers were only redirected to the post permalink if the post was actually paginated using the <!--nextpage--> marker.

Follow-up to [34492].

Props jeremyfelt, prografika, sachit.tandukar, subrataemfluence, hronak, ekatherine, henry.wright, chesio, dd32, SergeyBiryukov.
Fixes #40773. See #45337, #28081, #11694.

[SergeyBiryukov]

Replying to jeremyfelt:

There are (at least) two ways in which this presents itself:

First: when a request is made to any is_singular() post/page with /2/ appended to the URL, WordPress checks for an instance of <!--nextpage--> in the content. If it exists, and it matches the page number, $success is set to true and the page is loaded. If the next page marker does not exist, there is no current check that flags the content for 404 if a page number is part of the URL. For that, we could do something like 45337.diff​ to return a 404 if content is not paged.

Second: (highlighted in the ticket description), when a page is set as the page_for_posts, is_singular() is false and the logic handling <!--nextpage--> is skipped entirely. Earlier in the process, the query object was populated with posts, so as far as handle_404() is concerned, is_home() is true and the page can be loaded as is. The fix for this seems a little more complicated and _could_ be handled earlier in the process.

Thanks for the detailed comment!

[47727] should fix the first item, let's keep the ticket open for the second item.

[SergeyBiryukov]

In 47738:

Query: Simplify the logic in WP::handle_404() to allow for easier modifications.

See #45337.

[SergeyBiryukov]

In 47760:

Canonical: Redirect paged requests for a static page assigned as the "Posts page".

This avoids displaying duplicate content of the home page under different URLs with appended page numbers.

This change only affects the <!--nextpage--> pagination (page query variable) and not the regular multiple posts pagination (paged query variable).

The posts page does not support the <!--nextpage--> pagination, so requests for invalid page numbers should be redirected to the page permalink, applying the logic previously implemented for single posts or pages.

Follow-up to [34492], [47727].

Props jeremyfelt, sachit.tandukar, SergeyBiryukov.
Fixes #45337. See #40773, #28081, #11694.

[SergeyBiryukov]

In 47761:

Canonical: Only redirect non-existing page requests to the post permalink if the post is found.

Follow-up to [47760].

See #45337, #40773, #28081, #11694.

[SergeyBiryukov]

In 47781:

Tests: Give canonical test fixtures for paginated content more descriptive names.

Follow-up to [47727].

See #28081, #40773, #45337.