Failed upgrades lead to NullPointerException in ConfluenceGroupJoiningAuthenticator

Symptom

User cannot log in:

In the atlassian-confluence.log file the following is reported:

java.lang.NullPointerException
at com.atlassian.crowd.embedded.core.CrowdServiceImpl.isUserMemberOfGroup(CrowdServiceImpl.java:265)
at com.atlassian.confluence.user.ConfluenceGroupJoiningAuthenticator.addUserToGroup(ConfluenceGroupJoiningAuthenticator.java:59)
at com.atlassian.confluence.user.ConfluenceGroupJoiningAuthenticator$1.doInTransactionWithoutResult(ConfluenceGroupJoiningAuthenticator.java:48)
at org.springframework.transaction.support.TransactionCallbackWithoutResult.doInTransaction(TransactionCallbackWithoutResult.java:33)
at org.springframework.transaction.support.TransactionTemplate.execute(TransactionTemplate.java:127)

Cause

This is can be due to several issues leading to failed upgrades to Confluence 3.5. For more information, refer to the Confluence log file. Some issues where we have seen this include:

• A user was matched that did not have a username attribute.
• The LDAP server had a limit on the maximum number of results it can return.

In all cases, the upgrade failure causes the internal directory to be in an inconsistent state, possibly missing the atlassian-user group, which can cause this error.

Resolution

The error should be handled better and a more meaningful error message should be logged by ConfluenceGroupJoiningAuthenticator.