Site logo returns image attachment when no logo is defined

[greenshady]

This is a regression that seems to have cropped up from this change: https://core.trac.wordpress.org/changeset/58213

Ticket: https://core.trac.wordpress.org/ticket/60922

To reproduce, activate the Twenty Twenty-Four theme on your site but do not set a logo for the site. Ensure that the Site Logo block is in the header (it is by default).

View any page on the site, you shouldn't see a logo. View an image attachment page, the logo will use the attached image instead.

[greenshady]

Attachment image being used for site logo.

[joedolson]

The problem is that has_custom_logo() now uses wp_attachment_is_image(), which uses the $post global if no value is passed. Need to exit earlier in has_custom_logo().

[joedolson]

Only execute wp_attachment_is_image if there is a value in site logo.

[joedolson]

Thanks, @greenshady!

[greenshady]

Tested the patch. It's working for me.

[krupajnanda]

Hey @greenshady

I was trying to test this fix. I am not pretty sure if I have followed the correct steps. But it would be helpful if you could point me to the right direction. Please check the attachment and what it says.

[hmbashar]

showing this error, doesn't work for me

[rajinsharwar]

Refreshed patch

[rajinsharwar]

Hi @hmbashar @krupajnanda, it seems that the lines upstream have changed compared to patch 61408. Please try this new one: 61408.2.diff

I have tested the fix myself, and it does seem to work.
Before: ​https://img001.prntscr.com/file/img001/0UfuioC6S52gevPD9b6e3A.png
After: ​https://img001.prntscr.com/file/img001/XnyPGihER4arXIVLxCbHOg.png ✅

Note for testers: Please know that attachment pages are disabled by default from 6.4. So, you can visit wp-admin/options.php on your site, search for wp_attachment_pages_enabled, and change the option to 1 to enable the option for testing.

As it's a relatively small change, and already has two manual tests, marking this for commit.

[joedolson]

In 58407:

Themes: Fix attachment rendered as site logo on attachment page.

Fix issue where the attachment thumbnail would be rendered as the site logo on attachment single templates if no site logo is set. Avoid calling wp_attachment_is_image() with no value, since that function will fallback to the global $post variable. Follow up to [58213]. See #60922.

Props greenshady, krupajnanda, hmbashar, rajinsharwar, joedolson.
Fixes #61408.