Users who have reached their personal project limit cannot fork to group

https://gitlab.zendesk.com/agent/tickets/82935

Summary

Before our upgrade to Gitlab EE 9.5.4 our users with "0" as personal project limit could fork projects to the groups they belong to (but not to their personal space) which we consider as expected behavior. After the upgrade all our users get a tooltip message saying that they can't fork the project due to their limit being reached. On the other hand they can fork the project if they access the URL: https://<domain>/<group-name>/<project-name> /forks/new

What is the current bug behavior?

Users that have reached their personal project limit can no longer fork projects to groups they belong to.

What is the expected correct behavior?

A user should not be able to fork projects to their personal namespace but they should still be able to fork to a group.