Permalink conflict: image attachment page and post when permalink setting is /%postname%/

[augustas]

Here is scenario when there is a permalink conflict between the "attachment page" URL and post when image filename and post name are equal:
Permalinks are set to /%postname%/

Using Media -> Library -> upload new image called about-me.jpg
System saves into "wp_posts" database table: post_name = "about-me"

I publish a new POST with the title "About Me". For this post database stores the post_name = "about-me"

If I go to URL: www.example.com/about-me/ - I am redirected to about-me.jpg Image Attachment Page.

If POST is created first and the image uploaded second - URL will open the POST.

This issue is similar to #13459

[SergeyBiryukov]

#15665, #21216, #21501

[SergeyBiryukov]

Reopening per ticket:15665:28, as #15665 only covered pages.

[aaroncampbell]

I ran into this yesterday. I definitely think that posts should take precedence over attachments in this case. Especially since the UI to change media slugs is hidden in screen options by default.

[SergeyBiryukov]

Introduced in [18541], specifically with the changes in WP_Rewrite::page_rewrite_rules().

24612.patch​ fixes it for me.

[aaroncampbell]

24612.patch​ works for me. It's very specific to "post" though. Do we want to assume that handling slug conflicts for custom post types should be done in the plugin that creates the post type?

[SergeyBiryukov]

A workaround:

function wp24612_resolve_post_vs_attachment_permalink_conflict( $query ) {
	if ( is_admin() || ! $query->is_main_query() ) {
		return;
	}

	if ( ! preg_match( "/^[^%]*%(?:postname)%/", get_option( 'permalink_structure' ) ) ) {
		return;
	}

	if ( empty( $query->queried_object ) || '' === $query->get( 'pagename' ) ) {
		return;
	}

	if ( 'attachment' === $query->queried_object->post_type ) {
		// See if we also have a post with the same slug
		$post = get_page_by_path( $query->get( 'pagename' ), OBJECT, 'post' );
		if ( $post ) {
			$query->queried_object    = $post;
			$query->queried_object_id = (int) $post->ID;
			$query->is_page           = false;
			$query->is_single         = true;
		}
	}
}
add_action( 'parse_query', 'wp24612_resolve_post_vs_attachment_permalink_conflict' );

[dmchale]

Thanks for that workaround @SergeyBirukov it worked perfectly on one of my client sites. (the latest patch did not. I tried to update query.php with the code changes in that patch manually, just to see if it was viable, but it seems the fact that the code did not set queried_object_id or is_single was causing problems)

Unfortunately, this issue has bitten me TWICE in the past 2 weeks at my day job, after 3 years of never having knowingly run into it before. I think a good part of the trouble stems from our SEO department wanting to ensure that all of our file names are now "search engine friendly" and as such have been trying to name documents and images more intelligently now on our client sites. Due to this, they HAPPEN to be naming some images/files the same as other objects within the system and it's causing issues when all of a sudden a section of the website "disappears" and site visitors are redirected to a PDF file rather than the content they were supposed to be served.

I did a bit of testing at home on my VVV setup tonight, and documented some of my steps and my findings as I went. I would love to help talk through a workaround that could be implemented in core, if possible. Since I don't have any history with how/why things were made getting to this point, I'm not sure why some design decisions were made. I did go through all of the tickets referenced by this ticket though, so I have at least read up a good deal on some others' issues with dealing with the same thing.

My notes are below..... apologies for length, I tried to be thorough.

start with clean install of trunk
set permalinks to /%post-name%/

created "Permalink" PAGE (system gave it a slug of /permalink/)
created "Permalink" POST (system gave it a slug of /permalink/)

Already have a conflict. Why can POSTS create a shared slug as PAGES?

uploaded permalink.pdf (system gave it a slug of /permalink-2/)

• Side note, the "permalink" shown at the top of the page still shows the native /attachment_id=N format, which obviously does not match my permalink setting. Is this by design, or something that should be addressed? It's misleading at best.

View /permalink/, system displays the PAGE content
Edit PAGE, update permalink to /permalink-page/

Refresh /permalink/, system now displays the POST content

• While a PAGE and POST existed with the name conflict, the PAGE always "won"

Edit POST, update permalink to /permalink-post/

Refresh /permalink/, WP now redirects to /permalink-post/

Upload permalink-post.pdf (system gave it a slug of /permalink-post-2/)
No conflict!

<Conclusion: you cannot create a slug conflict by uploading media files after an existing post type "owns" the slug> ..... Challenge: Is this true for all post types, CPTs included, or only pages/posts? Need to test.

Upload permalink-file.pdf (system gave it a slug of /permalink-file/)
Create POST called "permalink file" (system gave it a slug of /permalink-file/)
Viewed /permalink-file/, system shows the media page with a link to download the PDF

<Conclusion: you CAN create a post that will cause a naming conflict with a pre-existing media library item (as well as PAGE)>

Deleted "permalink file" POST, removed it from trash

Create PAGE called "permalink file" (system gave it a slug of /permalink-file-2/)
No conflicts!

<Conclusion: Add New Page behavior respects `attachment` post types, while Add New Post does not>

Takeaways....

• It is currently impossible to create a naming conflict between pages/attachments. No matter which you create first, the second one will pick a unique slug.

• Add/Edit Post should be updated to mimic Add New Page functionality, at least in regards to preventing naming conflicts with attachment post types.

• Permalinks/slugs have been demoted in the media library to the point of obvious confusion.
• - The current behavior of the system to use the slug as a permalink, but never SAYS this is the case. This seems to be a massive UI failure.
• - Slug editing is disabled from Screen Options by default, which makes things even more challenging to troubleshoot in this scenario

• Would suggest that "Permalinks" on the media edit page be updated to behave the same way pages/posts do, so the slug can be modified in place at the end of the url.
• - The screen could also CONTINUE to show the permanent link to the /?attachment_id=N url as well below, which would remain unchangeable.

• Bottom line, my belief is that the post/page/attachment post types should all respect each other out of the box and never create naming conflicts with each other. The matter of whether this is done ONLY when WP is set to /%post-name%/ setting, or always, can easily be a talking point. If naming conflicts were created because of/during the changing of the permalink setting, that's something a site admin could/would/(should?) have to address at that time. That job could even be plugin territory, an opportunity for someone to write a tool that would address that for people.

[SergeyBiryukov]

Related: #13459, #21970.

[SergeyBiryukov]

@dmchale, thanks for a thorough comment.

created "Permalink" PAGE (system gave it a slug of /permalink/)
created "Permalink" POST (system gave it a slug of /permalink/)
Already have a conflict. Why can POSTS create a shared slug as PAGES?

#13459 should resolve that.

uploaded permalink.pdf (system gave it a slug of /permalink-2/)
Side note, the "permalink" shown at the top of the page still shows the native /attachment_id=N format, which obviously does not match my permalink setting. Is this by design, or something that should be addressed? It's misleading at best.

Should be fixed in #1914, see [34690] (currently broken in trunk though due to [35195]).

Bottom line, my belief is that the post/page/attachment post types should all respect each other out of the box and never create naming conflicts with each other.

Let's try to fix that in #13459, left a comment there.

24612.2.patch​ is a refreshed patch with a unit test.

For reference, some of this functionality may (or may not) have changed in #18962.

[moisb]

Hi. Today I experienced this problem here. A user upload an image by bbPress named "tag.png" and my tags base is "tag". Result: All pages /tag/ stopped working returning 404 error. And even excluding the image of media library the slug /tag/ not returned to work and I was forced to modify the tags base.

How do I fix it? The workaround of @SergeyBiryukov works? I put this it on my theme functions.php?

[wonderboymusic]

In 35679:

Rewrite: alleviate conflicts between image attachment pages and posts when permalink structure is /%postname%/.

Adds unit test.

Props SergeyBiryukov.
Fixes #24612.

[SergeyBiryukov]

Replying to moisb:

A user upload an image by bbPress named "tag.png" and my tags base is "tag". Result: All pages /tag/ stopped working returning 404 error. And even excluding the image of media library the slug /tag/ not returned to work and I was forced to modify the tags base.

This sounds like a related, but different issue, since it's a clash between an attachment and a taxonomy rather than an attachment and a post.

I could not reproduce this on a clean install neither in 4.3 nor in 4.4-beta4. Please create a new ticket if still relevant.