Sync: Fix issue with syncing raw URLs for multisites

[ebinnion]

Fixes #7997

In #7997, @enejb reported an issue where his multisite was syncing an incorrect URL, the base URL for the site. This was caused by #5852 when we/I started syncing the raw URLs.

While I did test multisites, I apparently didn't test multisites with the constant set. Or, I would've noticed the wrong URL was being synced.

I was able to narrow this down to these lines in core WordPress:

// WP_HOME and WP_SITEURL should not have any effect in MS
remove_filter( 'option_siteurl', '_config_wp_siteurl' );
remove_filter( 'option_home',    '_config_wp_home'    );

The _config_wp_siteurl and _config_wp_home filters check if the WP_HOME or WP_SITEURL constants are set, and if so, uses those constants. BUT ... the filters that call those functions are removed for multisites.

In #5852, I was always returning the constant value, which is the incorrect behavior.

To test:

• Connect a subsite on a network
• Run a full sync and ensure values are synced correctly in network admin

[enejb]

Can we add a test here?
So that is a bit more clear what is going on.

[enejb]

Also Can you explain what the process will be in fixing sites that are broken?
Do we have to ask the user to reconnect? Will they be fixed by when the plugin update happens?

[ebinnion]

Existing test is now updated.

Also Can you explain what the process will be in fixing sites that are broken? Do we have to ask the user to reconnect? Will they be fixed by when the plugin update happens?

The sites should update automatically after plugin upgrade, once callables sync. If that fails, the user can initiate a full sync or cycle the connection.

[lezama]

[oskosk]