We try to avoid this at all cost but at times (when users get married for example) we must change that users network name. We are using CROWD and LDAP to manage users in JIRA.
The problem is, if that user's LDAP login name is changed, CROWD will treat them like a brand new user and they lose the history of all JIRA work from the old users name.
We are in desperate need of an administration procedure to fix this name change from the JIRA issues database. This issue must come up for other customers and we need to document a procedure to handle this situation as best we can. We also have an identical issue with Confluence but for now, I am focusing on fixing the JIRA issue.