NullPointerException when reverting non-copy targets

https://github.com/zanata/zanata-server/blob/server-3.7.3/zanata-war/src/main/java/org/zanata/service/impl/TranslationServiceImpl.java#L1010

Time: 2015-10-20T09:29:53Z
req.remoteHost: 10.4.129.133
req.userAgent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/46.0.2490.71 Safari/537.36
req.requestURI: /zanata/seam/resource/gwt
req.requestURL: http://translate.zanata.org/zanata/seam/resource/gwt
ERROR org.zanata.webtrans.server.SeamDispatch
Error dispatching action: java.lang.NullPointerException

server.log
java.lang.NullPointerException
at org.zanata.service.impl.TranslationServiceImpl.revertTranslations(TranslationServiceImpl.java:1010)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at org.jboss.seam.util.Reflections.invoke(Reflections.java:22)
at org.jboss.seam.intercept.RootInvocationContext.proceed(RootInvocationContext.java:32)
at org.jboss.seam.intercept.SeamInvocationContext.proceed(SeamInvocationContext.java:56)
at org.zanata.async.AsyncMethodInterceptor.aroundInvoke(AsyncMethodInterceptor.java:46)
at org.jboss.seam.intercept.SeamInvocationContext.proceed(SeamInvocationContext.java:68)
at org.jboss.seam.transaction.RollbackInterceptor.aroundInvoke(RollbackInterceptor.java:28)
at org.jboss.seam.intercept.SeamInvocationContext.proceed(SeamInvocationContext.java:68)
at org.jboss.seam.core.BijectionInterceptor.aroundInvoke(BijectionInterceptor.java:79)
at org.jboss.seam.intercept.SeamInvocationContext.proceed(SeamInvocationContext.java:68)
at org.jboss.seam.transaction.TransactionInterceptor$1.work(TransactionInterceptor.java:97)
at org.jboss.seam.util.Work.workInTransaction(Work.java:61)
at org.jboss.seam.transaction.TransactionInterceptor.aroundInvoke(TransactionInterceptor.java:91)
at org.jboss.seam.intercept.SeamInvocationContext.proceed(SeamInvocationContext.java:68)
at org.jboss.seam.core.MethodContextInterceptor.aroundInvoke(MethodContextInterceptor.java:44)
at org.jboss.seam.intercept.SeamInvocationContext.proceed(SeamInvocationContext.java:68)
at org.jboss.seam.intercept.RootInterceptor.invoke(RootInterceptor.java:107)
at org.jboss.seam.intercept.JavaBeanInterceptor.interceptInvocation(JavaBeanInterceptor.java:196)
at org.jboss.seam.intercept.JavaBeanInterceptor.invoke(JavaBeanInterceptor.java:114)
at org.zanata.service.impl.TranslationServiceImpl_$$javassist_seam_96.revertTranslations(TranslationServiceImpl$$_javassist_seam_96.java)
at org.zanata.webtrans.server.rpc.RevertTransUnitUpdatesHandler.execute(RevertTransUnitUpdatesHandler.java:84)
at org.zanata.webtrans.server.rpc.RevertTransUnitUpdatesHandler.execute(RevertTransUnitUpdatesHandler.java:49)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at org.jboss.seam.util.Reflections.invoke(Reflections.java:22)
at org.jboss.seam.intercept.RootInvocationContext.proceed(RootInvocationContext.java:32)
at org.jboss.seam.intercept.SeamInvocationContext.proceed(SeamInvocationContext.java:56)
at org.jboss.seam.transaction.RollbackInterceptor.aroundInvoke(RollbackInterceptor.java:28)
at org.jboss.seam.intercept.SeamInvocationContext.proceed(SeamInvocationContext.java:68)
at org.jboss.seam.core.BijectionInterceptor.aroundInvoke(BijectionInterceptor.java:79)
at org.jboss.seam.intercept.SeamInvocationContext.proceed(SeamInvocationContext.java:68)
at org.jboss.seam.core.MethodContextInterceptor.aroundInvoke(MethodContextInterceptor.java:44)
at org.jboss.seam.intercept.SeamInvocationContext.proceed(SeamInvocationContext.java:68)
at org.jboss.seam.intercept.RootInterceptor.invoke(RootInterceptor.java:107)
at org.jboss.seam.intercept.JavaBeanInterceptor.interceptInvocation(JavaBeanInterceptor.java:196)
at org.jboss.seam.intercept.JavaBeanInterceptor.invoke(JavaBeanInterceptor.java:114)
at org.zanata.webtrans.server.rpc.RevertTransUnitUpdatesHandler_$$javassist_seam_177.execute(RevertTransUnitUpdatesHandler$$_javassist_seam_177.java)
at org.zanata.webtrans.server.SeamDispatch.doExecute(SeamDispatch.java:157)
at org.zanata.webtrans.server.SeamDispatch.execute(SeamDispatch.java:137)
at sun.reflect.GeneratedMethodAccessor11034.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at org.jboss.seam.util.Reflections.invoke(Reflections.java:22)
at org.jboss.seam.intercept.RootInvocationContext.proceed(RootInvocationContext.java:32)
at org.jboss.seam.intercept.SeamInvocationContext.proceed(SeamInvocationContext.java:56)
at org.jboss.seam.transaction.RollbackInterceptor.aroundInvoke(RollbackInterceptor.java:28)
at org.jboss.seam.intercept.SeamInvocationContext.proceed(SeamInvocationContext.java:68)
at org.jboss.seam.core.MethodContextInterceptor.aroundInvoke(MethodContextInterceptor.java:44)
at org.jboss.seam.intercept.SeamInvocationContext.proceed(SeamInvocationContext.java:68)
at org.jboss.seam.intercept.RootInterceptor.invoke(RootInterceptor.java:107)
at org.jboss.seam.intercept.JavaBeanInterceptor.interceptInvocation(JavaBeanInterceptor.java:196)
at org.jboss.seam.intercept.JavaBeanInterceptor.invoke(JavaBeanInterceptor.java:114)
at org.zanata.webtrans.server.SeamDispatch_$$javassist_seam_20.execute(SeamDispatch$$_javassist_seam_20.java)
at org.zanata.webtrans.server.GwtDispatchService$1.process(GwtDispatchService.java:47)
at org.jboss.seam.servlet.ContextualHttpServletRequest.run(ContextualHttpServletRequest.java:65)
at org.zanata.webtrans.server.GwtDispatchService.execute(GwtDispatchService.java:49)
at sun.reflect.GeneratedMethodAccessor11033.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at com.google.gwt.user.server.rpc.RPC.invokeAndEncodeResponse(RPC.java:561)
at com.google.gwt.user.server.rpc.RemoteServiceServlet.processCall(RemoteServiceServlet.java:265)
at com.google.gwt.user.server.rpc.RemoteServiceServlet.processPost(RemoteServiceServlet.java:305)
at com.google.gwt.user.server.rpc.AbstractRemoteServiceServlet.doPost(AbstractRemoteServiceServlet.java:62)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:754)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:847)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:295)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:214)
at net.bull.javamelody.MonitoringFilter.doFilter(MonitoringFilter.java:164)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:246)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:214)
at org.tuckey.web.filters.urlrewrite.RuleChain.handleRewrite(RuleChain.java:176)
at org.tuckey.web.filters.urlrewrite.RuleChain.doRules(RuleChain.java:145)
at org.tuckey.web.filters.urlrewrite.UrlRewriter.processRequest(UrlRewriter.java:92)
at org.tuckey.web.filters.urlrewrite.UrlRewriteFilter.doFilter(UrlRewriteFilter.java:389)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:246)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:214)
at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:83)
at org.jboss.seam.web.LoggingFilter.doFilter(LoggingFilter.java:60)
at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:73)
at org.jboss.seam.web.ExceptionFilter.doFilter(ExceptionFilter.java:64)
at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
at org.jboss.seam.servlet.SeamFilter.doFilter(SeamFilter.java:158)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:246)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:214)
at org.zanata.seam.interceptor.MonitoringWrapper.doFilter(MonitoringWrapper.java:67)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:246)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:214)
at org.zanata.servlet.GWTCacheControlFilter.doFilter(GWTCacheControlFilter.java:61)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:246)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:214)
at org.zanata.servlet.MDCInsertingServletFilter.doFilter(MDCInsertingServletFilter.java:91)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:246)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:214)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:231)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:149)
at org.jboss.as.jpa.interceptor.WebNonTxEmCloserValve.invoke(WebNonTxEmCloserValve.java:50)
at org.jboss.as.jpa.interceptor.WebNonTxEmCloserValve.invoke(WebNonTxEmCloserValve.java:50)
at org.jboss.security.negotiation.NegotiationAuthenticator$WrapperValve.invoke(NegotiationAuthenticator.java:490)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:420)
at org.jboss.as.web.security.SecurityContextAssociationValve.invoke(SecurityContextAssociationValve.java:169)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:150)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:97)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:102)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:344)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:854)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:653)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:926)
at java.lang.Thread.run(Thread.java:745)