Problem

In Confluence 8.5.x, personal spaces for users with spaces in their usernames (e.g., ~test 4) worked correctly. However, after upgrading to Confluence 9.1 and onwards, personal spaces for these users fail to load.

Although Confluence does not allow creating usernames with spaces manually, it does not block usernames with spaces when they are synced from LDAP or Active Directory. In 9.1 onward versions, these users can still log in, but their personal spaces can't be accessed or created.

Environment

Confluence DC 9.1 and onward

Steps to Reproduce

1. Deploy a vanilla Confluence 9.2 instance.
2. Create a new user in the instance with a blank space in its name (this user needs to be either synced from an external directory or created via JIT).
3. Log in to the instance with the new user.
4. Try to create a personal space for this user.

Expected Results

The personal space should load/create successfully for external users with spaces in their usernames, just like in Confluence 8.5.x.

Actual Results

The personal space does not load/create, and users receive an error.

Workaround

N/A

Notes