Trusted authentication doesn't work for Confluence users with uppercase usernames

Trying to use the trusted authentication feature of the Jiraissues macro doesn't work when a user's username is uppercase. JIRA shows the following in its log:

2008-01-23 13:59:48,104 INFO [STDOUT] 2008-01-23 13:59:48,104 ajp-0.0.0.0-6103-8 WARN [atlassian.seraph.filter.TrustedApplicationsFilter] User 'BOB' referenced by trusted application: 'confluence:7521898' is not found.

To reproduce:

1. Have an LDAP repository with a username with uppercase letters, BOB. The LDAP server should do case-insensitive authentication, like in Active Directory.
2. Connect Confluence and JIRA to the LDAP repository. JIRA for authentication only via OSUser, Confluence via Atlassian-User.
3. Set up a local user for 'bob' in JIRA, which must be lowercase because all JIRA usernames must be lowercase.
4. Log in to Confluence as 'bob' (or 'BOB', it doesn't matter). Confluence creates the user as 'BOB', because it respects the case of the underlying system.
5. Use an authenticated

macro to retrieve issues from JIRA as 'BOB'.
6. The above error message appears in the JIRA log, which can't authenticate 'BOB'.

Note that the most common case for installations using trusted authentication is with an external user repository like LDAP, so this is a serious problem for the trusted authentication feature.