Multisite sites without a path redirect to signup page

[Ipstenu]

From ​https://wordpress.org/support/topic/after-update-to-39-one-sub-site-directs-to-wp-signupphpnew?replies=4&view=all

Pre 3.9, WordPress would treat an empty 'path' variable for the site as a /

As of 3.9, this is no longer the case, and a blank path will act as if the site does not exist.

It's a simple fix in the admin section, but this is a regression from 3.8

[JPry]

A more comprehensive patch

[JPry]

Alternate method of fixing the reported issue

[danielkanchev]

This is not related to the sub-site issue but if a single WP site not part of a network has its "home" and "siteurl" set to 'NULL' (empty string) then the WP displays "Error establishing a database connection". Probably the fix for the sub-site issue should be a universal fix for this issue as well.

[SirLouen]

Looking at the support ticket that @Ipstenu is referencing

In network admin > sites > edit site > info
The second line is Path. There was nothing in the field for this site. For all sites working properly, there was a forward slash like so: /

This field doesn't exist anymore.

Going back to 3.9 there was this field ​https://github.com/WordPress/wordpress-develop/blob/3.9.0/src/wp-admin/network/site-info.php

This field was removed in 4.3, [32759]

It's true that if we manually remove nowadays the Path, it will break. We have to do this through database though, it's not straightforward to accomplish this (and undesirable to do so)

With the patch provided, the main site works, but when accessing Network Sites, it goes in a canonical loop

This report is weird because it has a modification date of 6 years ago, despite there has not been more discussion for 10 years. Probably a spam comment that was removed and altered the modification time.

For all these reasons, I would say that this has been already fixed, indirectly; hence I think it's safe to close this ticket now, as fixed: worksforme