From JRA-27353

Steps to reproduce:

1. install JIRA
2. setup LDAP directory - create test data (see below)
3. add LDAP directory in JIRA configuration with option "Enable Nested Groups" enabled
4. synchronize data
5. change name of "sub_group" to "Sub_group" and update uniqueMember parameter of parent_group to match changed name
6. synchronize data again - here crowd should fail on inserting data into database (CWD_MEMBERSHIP table)

I was able to reproduce it with HSQL and PostgreSQL.

Test data - two groups with relation:

parent_group, uniqueMember=

sub_group

LDIF export of my test data (I've configured LDAP to use root entity dc=atlassian,dc=pl):
parent_group.ldif

version: 1

dn: cn=parent_group,dc=atlassian,dc=pl
objectClass: groupOfUniqueNames
cn: parent_group
uniqueMember: cn=sub_group,dc=atlassian,dc=pl
description: Parent group

sub_group.ldif

version: 1

dn: cn=sub_group,dc=atlassian,dc=pl
objectClass: groupOfUniqueNames
cn: sub_group
uniqueMember:
description: Child group

Also to see effect of exception which you should get in step 6 you may add user and set membership using uniqueMember attribute - this user won't be added to any group because of synchronization fail (user should be created, groups also, but no user membership in group will be created).