Default realm users that differ only by case break the user administration screen in new DB

1. Fire up Nexus 3.37.3 against a PostgreSQL database.
2. Make two default realm users, one with user ID "test", the other with "Test".
3. Try loading the security--> users screen

The screen will not load, it says "a database error occurred". The logs show the stack below.

Expected: Default realm user ID's are case sensitive. This is by design, and can't be changed at this point since existing users are depending on this behavior. So the above should not break the UI both users should be visible.

Workaround: The only way to fix this is to manually remove one of the users from the database.

# delete from security_user where id='Test';
# delete from user_role_mapping where user_id='Test';

2022-01-07 13:08:28,631-0600 ERROR [qtp1321848228-678] admin org.sonatype.nexus.extdirect.internal.ExtDirectExceptionHandler - Failed to invoke action method: coreui_User.read, java-method: org.sonatype.nexus.coreui.UserComponent.read
org.apache.ibatis.exceptions.TooManyResultsException: Expected one result (or null) to be returned by selectOne(), but found: 2
at org.apache.ibatis.session.defaults.DefaultSqlSession.selectOne(DefaultSqlSession.java:80)
at org.apache.ibatis.binding.MapperMethod.execute(MapperMethod.java:87)
at org.apache.ibatis.binding.MapperProxy$PlainMethodInvoker.invoke(MapperProxy.java:145)
at org.apache.ibatis.binding.MapperProxy.invoke(MapperProxy.java:86)
at com.sun.proxy.$Proxy149.read(Unknown Source)
at org.sonatype.nexus.internal.security.model.CUserRoleMappingDAO.read(CUserRoleMappingDAO.java:42)
at java.lang.invoke.MethodHandle.invokeWithArguments(MethodHandle.java:627)
at org.apache.ibatis.binding.MapperProxy$DefaultMethodInvoker.invoke(MapperProxy.java:159)
at org.apache.ibatis.binding.MapperProxy.invoke(MapperProxy.java:86)
at com.sun.proxy.$Proxy149.read(Unknown Source)
at org.sonatype.nexus.internal.security.model.SecurityConfigurationImpl.getUserRoleMapping(SecurityConfigurationImpl.java:323)
at org.sonatype.nexus.transaction.TransactionalWrapper.proceedWithTransaction(TransactionalWrapper.java:58)
at org.sonatype.nexus.transaction.TransactionInterceptor.proceedWithTransaction(TransactionInterceptor.java:66)
at org.sonatype.nexus.transaction.TransactionInterceptor.invoke(TransactionInterceptor.java:55)
at org.sonatype.nexus.security.internal.SecurityConfigurationManagerImpl.readUserRoleMapping(SecurityConfigurationManagerImpl.java:314)
at org.sonatype.nexus.security.internal.UserManagerImpl.getUsersRoles(UserManagerImpl.java:239)
at org.sonatype.nexus.security.internal.UserManagerImpl.toUser(UserManagerImpl.java:123)
at org.sonatype.nexus.security.internal.UserManagerImpl.listUsers(UserManagerImpl.java:154)
at org.sonatype.nexus.security.internal.UserManagerImpl.searchUsers(UserManagerImpl.java:260)
at org.sonatype.nexus.security.internal.DefaultSecuritySystem.searchUsers(DefaultSecuritySystem.java:423)
at org.sonatype.nexus.security.SecuritySystem$searchUsers$0.call(Unknown Source)
at org.sonatype.nexus.coreui.UserComponent.read(UserComponent.groovy:104)
at com.palominolabs.metrics.guice.ExceptionMeteredInterceptor.invoke(ExceptionMeteredInterceptor.java:23)
at com.palominolabs.metrics.guice.TimedInterceptor.invoke(TimedInterceptor.java:26)
at org.apache.shiro.guice.aop.AopAllianceMethodInvocationAdapter.proceed(AopAllianceMethodInvocationAdapter.java:49)
at org.apache.shiro.authz.aop.AuthorizingAnnotationMethodInterceptor.invoke(AuthorizingAnnotationMethodInterceptor.java:68)
at org.apache.shiro.guice.aop.AopAllianceMethodInterceptorAdapter.invoke(AopAllianceMethodInterceptorAdapter.java:36)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)