stem copy in ui should give friendly error if stem already exists

2016-07-21 14:23:01,271: [TP-Processor2] ERROR GrouperUiRestServlet.doGet(324) - Problem calling reflection from URL: edu.internet2.middleware.grouper.grouperUi.serviceLogic.UiV2Stem.stemCopySubmit

edu.internet2.middleware.grouper.exception.StemAddAlreadyExistsException: Stem exists: penn:sas:template:mailing_list,
Problem in HibernateSession: HibernateSession (3f0b3760): new, notReadonly, READ_WRITE_NEW, notActiveTransaction, session (a0d6de7),
Problem calling method stemCopySubmit on edu.internet2.middleware.grouper.grouperUi.serviceLogic.UiV2Stem
at edu.internet2.middleware.grouper.Stem.internal_addChildStem(Stem.java:2681)
at edu.internet2.middleware.grouper.Stem$14.callback(Stem.java:4052)
at edu.internet2.middleware.grouper.hibernate.HibernateSession.callbackHibernateSession(HibernateSession.java:700)
at edu.internet2.middleware.grouper.Stem.internal_copy(Stem.java:4016)
at edu.internet2.middleware.grouper.StemCopy.save(StemCopy.java:131)
at edu.internet2.middleware.grouper.grouperUi.serviceLogic.UiV2Stem.stemCopySubmit(UiV2Stem.java:507)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at edu.internet2.middleware.grouper.util.GrouperUtil.invokeMethod(GrouperUtil.java:4112)
at edu.internet2.middleware.grouper.util.GrouperUtil.callMethod(GrouperUtil.java:4063)
at edu.internet2.middleware.grouper.j2ee.GrouperUiRestServlet.doGet(GrouperUiRestServlet.java:291)
at edu.internet2.middleware.grouper.j2ee.GrouperUiRestServlet.doPost(GrouperUiRestServlet.java:163)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.owasp.csrfguard.CsrfGuardFilter.doFilter(CsrfGuardFilter.java:110)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at edu.internet2.middleware.grouper.ui.GrouperUiFilter.doFilter(GrouperUiFilter.java:1025)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at edu.upenn.isc.proxyWrapper.ProxyWrapperFilter.doFilter(ProxyWrapperFilter.java:50)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:286)
at org.apache.jk.server.JkCoyoteHandler.invoke(JkCoyoteHandler.java:190)
at org.apache.jk.common.HandlerRequest.invoke(HandlerRequest.java:283)
at org.apache.jk.common.ChannelSocket.invoke(ChannelSocket.java:767)
at org.apache.jk.common.ChannelSocket.processConnection(ChannelSocket.java:697)
at org.apache.jk.common.ChannelSocket$SocketConnection.runIt(ChannelSocket.java:889)
at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:690)
at java.lang.Thread.run(Thread.java:662)