Fix synchronisation of Users to Contacts in WordPress Multisite

[christianwach]

Overview

In WordPress Multisite, only Users present on a particular Site should be synced to CiviCRM. At present, all WordPress Users are synced to CiviCRM regardless of their Site membership.

Before

All WordPress Users from all Sites are synced to CiviCRM.

After

Only WordPress Users that are members of that Sub-site are synced to CiviCRM.

Comments

Fixes this issue on CiviCRM Lab

[civibot]

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[kcristiano]

Thanks @christianwach

• (r-explain) Pass
• (r-test) Pass
• (r-code) Pass
• (r-doc) Pass
• (r-maint) Pass
• (r-run) Pass: We have had this on all client sites sinc 5.10.x We did not have any issues.
• (r-user) Pass: Without this PR there were unintended consequences in that contacts from multiple domain ids would all end up as users on the main site - whether they belonged or not.
• (r-tech) Pass

I believe this is merge ready. I do think we should update the docs https://docs.civicrm.org/user/en/latest/initial-set-up/users-contacts/#synchronize-users-to-contacts with a section on WP.

[eileenmcnaughton]

merging based on @kcristiano review