Complete Task in Tasklist throws NPE

// When

• I have a CMMN Task
• I complete it via Tasklist

// Then

• Server Response Status Code is 500
• The task is not completed

// Expected

• Server Response Status Code is 20X
• The task is completed

// Notes

• might or might not be related to CAM-10350
• Reproduced with "Review Invoice" Task of the Invoice example

   org.camunda.bpm.engine.rest.exception.ExceptionHandler.toResponse java.lang.NullPointerException
          at org.camunda.bpm.engine.impl.cmmn.entity.runtime.CaseExecutionEntity.setSuperExecution(CaseExecutionEntity.java:470)
          at org.camunda.bpm.engine.impl.cmmn.operation.AbstractAtomicOperationCaseExecutionComplete.postTransitionNotification(AbstractAtomicOperationCaseExecutionComplete.java:95)
          at org.camunda.bpm.engine.impl.cmmn.operation.AbstractCmmnEventAtomicOperation.eventNotificationsCompleted(AbstractCmmnEventAtomicOperation.java:44)
          at org.camunda.bpm.engine.impl.cmmn.operation.AbstractCmmnEventAtomicOperation.eventNotificationsCompleted(AbstractCmmnEventAtomicOperation.java:30)
          at org.camunda.bpm.engine.impl.core.operation.AbstractEventAtomicOperation.execute(AbstractEventAtomicOperation.java:66)
          at org.camunda.bpm.engine.impl.cmmn.operation.AbstractCmmnEventAtomicOperation.execute(AbstractCmmnEventAtomicOperation.java:30)
          at org.camunda.bpm.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:106)
          at org.camunda.bpm.engine.impl.cmmn.entity.runtime.CaseExecutionEntity.performOperationSync(CaseExecutionEntity.java:897)
          at org.camunda.bpm.engine.impl.core.operation.AbstractEventAtomicOperation.execute(AbstractEventAtomicOperation.java:62)
          at org.camunda.bpm.engine.impl.cmmn.operation.AbstractCmmnEventAtomicOperation.execute(AbstractCmmnEventAtomicOperation.java:30)
          at org.camunda.bpm.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:106)
          at org.camunda.bpm.engine.impl.cmmn.entity.runtime.CaseExecutionEntity.performOperation(CaseExecutionEntity.java:892)
          at org.camunda.bpm.engine.impl.cmmn.execution.CmmnExecution.complete(CmmnExecution.java:994)
          at org.camunda.bpm.engine.impl.cmmn.behavior.StageActivityBehavior.checkAndCompleteCaseExecution(StageActivityBehavior.java:470)
          at org.camunda.bpm.engine.impl.cmmn.behavior.StageActivityBehavior.handleChildCompletion(StageActivityBehavior.java:412)
          at org.camunda.bpm.engine.impl.cmmn.operation.AbstractAtomicOperationCaseExecutionComplete.postTransitionNotification(AbstractAtomicOperationCaseExecutionComplete.java:103)
          at org.camunda.bpm.engine.impl.cmmn.operation.AbstractCmmnEventAtomicOperation.eventNotificationsCompleted(AbstractCmmnEventAtomicOperation.java:44)
          at org.camunda.bpm.engine.impl.cmmn.operation.AbstractCmmnEventAtomicOperation.eventNotificationsCompleted(AbstractCmmnEventAtomicOperation.java:30)
          at org.camunda.bpm.engine.impl.core.operation.AbstractEventAtomicOperation.execute(AbstractEventAtomicOperation.java:66)
          at org.camunda.bpm.engine.impl.cmmn.operation.AbstractCmmnEventAtomicOperation.execute(AbstractCmmnEventAtomicOperation.java:30)
          at org.camunda.bpm.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:106)
          at org.camunda.bpm.engine.impl.cmmn.entity.runtime.CaseExecutionEntity.performOperationSync(CaseExecutionEntity.java:897)
          at org.camunda.bpm.engine.impl.core.operation.AbstractEventAtomicOperation.execute(AbstractEventAtomicOperation.java:62)
          at org.camunda.bpm.engine.impl.cmmn.operation.AbstractCmmnEventAtomicOperation.execute(AbstractCmmnEventAtomicOperation.java:30)
          at org.camunda.bpm.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:106)
          at org.camunda.bpm.engine.impl.interceptor.CommandContext$1.call(CommandContext.java:95)
          at org.camunda.bpm.engine.impl.interceptor.CommandContext$1.call(CommandContext.java:93)
          at org.camunda.bpm.engine.impl.context.ProcessApplicationClassloaderInterceptor.call(ProcessApplicationClassloaderInterceptor.java:48)
          at org.camunda.bpm.application.AbstractProcessApplication.execute(AbstractProcessApplication.java:121)
          at org.camunda.bpm.application.AbstractProcessApplication.execute(AbstractProcessApplication.java:132)
          at org.camunda.bpm.engine.impl.context.Context.executeWithinProcessApplication(Context.java:195)
          at org.camunda.bpm.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:93)
          at org.camunda.bpm.engine.impl.cmmn.entity.runtime.CaseExecutionEntity.performOperation(CaseExecutionEntity.java:892)
          at org.camunda.bpm.engine.impl.cmmn.execution.CmmnExecution.manualComplete(CmmnExecution.java:998)
          at org.camunda.bpm.engine.impl.persistence.entity.TaskEntity.complete(TaskEntity.java:297)
          at org.camunda.bpm.engine.impl.cmd.SubmitTaskFormCmd.execute(SubmitTaskFormCmd.java:92)
          at org.camunda.bpm.engine.impl.cmd.SubmitTaskFormCmd.execute(SubmitTaskFormCmd.java:43)
          at org.camunda.bpm.engine.impl.interceptor.CommandExecutorImpl.execute(CommandExecutorImpl.java:28)
          at org.camunda.bpm.engine.impl.interceptor.CommandContextInterceptor.execute(CommandContextInterceptor.java:107)
          at org.camunda.bpm.engine.impl.interceptor.ProcessApplicationContextInterceptor.execute(ProcessApplicationContextInterceptor.java:70)
          at org.camunda.bpm.engine.impl.interceptor.LogInterceptor.execute(LogInterceptor.java:33)
          at org.camunda.bpm.engine.impl.FormServiceImpl.submitTaskForm(FormServiceImpl.java:91)
          at org.camunda.bpm.engine.rest.sub.task.impl.TaskResourceImpl.submit(TaskResourceImpl.java:146)
          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)
          at org.jboss.resteasy.core.MethodInjectorImpl.invoke(MethodInjectorImpl.java:167)
          at org.jboss.resteasy.core.ResourceMethod.invokeOnTarget(ResourceMethod.java:257)
          at org.jboss.resteasy.core.ResourceMethod.invoke(ResourceMethod.java:222)
          at org.jboss.resteasy.core.ResourceLocator.invokeOnTargetObject(ResourceLocator.java:159)
          at org.jboss.resteasy.core.ResourceLocator.invoke(ResourceLocator.java:107)
          at org.jboss.resteasy.core.ResourceLocator.invokeOnTargetObject(ResourceLocator.java:154)
          at org.jboss.resteasy.core.ResourceLocator.invoke(ResourceLocator.java:92)
          at org.jboss.resteasy.core.SynchronousDispatcher.getResponse(SynchronousDispatcher.java:542)
          at org.jboss.resteasy.core.SynchronousDispatcher.invoke(SynchronousDispatcher.java:524)
          at org.jboss.resteasy.core.SynchronousDispatcher.invoke(SynchronousDispatcher.java:126)
          at org.jboss.resteasy.plugins.server.servlet.ServletContainerDispatcher.service(ServletContainerDispatcher.java:208)
          at org.jboss.resteasy.plugins.server.servlet.HttpServletDispatcher.service(HttpServletDispatcher.java:55)
          at org.jboss.resteasy.plugins.server.servlet.HttpServletDispatcher.service(HttpServletDispatcher.java:50)
          at javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
          at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
          at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
          at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
          at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
          at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
          at org.camunda.bpm.engine.rest.filter.CacheControlFilter.doFilter(CacheControlFilter.java:45)
          at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
          at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
          at org.camunda.bpm.engine.rest.filter.EmptyBodyFilter.doFilter(EmptyBodyFilter.java:99)
          at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
          at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
          at org.camunda.bpm.webapp.impl.security.filter.headersec.HttpHeaderSecurityFilter.doFilter(HttpHeaderSecurityFilter.java:83)
          at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
          at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
          at org.camunda.bpm.webapp.impl.security.filter.CsrfPreventionFilter.doFilter(CsrfPreventionFilter.java:165)
          at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
          at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
          at org.camunda.bpm.webapp.impl.security.filter.SecurityFilter.doFilterSecure(SecurityFilter.java:71)
          at org.camunda.bpm.webapp.impl.security.filter.SecurityFilter.doFilter(SecurityFilter.java:55)
          at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
          at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
          at org.camunda.bpm.webapp.impl.security.auth.AuthenticationFilter$1.execute(AuthenticationFilter.java:62)
          at org.camunda.bpm.webapp.impl.security.auth.AuthenticationFilter$1.execute(AuthenticationFilter.java:60)
          at org.camunda.bpm.webapp.impl.security.SecurityActions.runWithAuthentications(SecurityActions.java:44)
          at org.camunda.bpm.webapp.impl.security.auth.AuthenticationFilter.doFilter(AuthenticationFilter.java:60)
          at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
          at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
          at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:200)
          at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
          at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:490)
          at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139)
          at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)
          at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:678)
          at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74)
          at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343)
          at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:408)
          at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
          at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:836)
          at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1747)
          at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
          at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
          at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
          at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
          at java.lang.Thread.run(Thread.java:748)