[NIFI-1243] StandardProcessSession throws NPE when it attempts to close "currentReadClaimStream"

• Type: Bug
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 0.3.0
• Fix Version/s: 0.4.0
• Component/s: Core Framework
• Assignee: Oleg Zhurakousky
• Reporter: Oleg Zhurakousky
• Created: 02/Dec/15 20:55
• Updated: 02/Dec/15 21:28
• Resolved: 02/Dec/15 21:28

Description

The 'currentReadClaimStream' CAN be null in certain situations, so a simple null check (as it is done in many other places in the class) before close would address the issue.
Just as an FYI, the stack trace at the time of this bug being discovered is:

9cd1-4880-9609-2413910ef89c] due to uncaught Exception:
2015-12-02 13:18:03,267 WARN [Event-Driven Process Thread-5] o.a.n.c.s.EventDrivenSchedulingAgent
java.lang.NullPointerException: null
        at org.apache.nifi.controller.repository.StandardProcessSession.read(StandardProcessSession.java:1810) ~[nifi-framework-core-0.4.0-SNAPSHOT.jar:0.4.0-SNAPSHOT]
        at org.apache.nifi.controller.repository.StandardProcessSession.read(StandardProcessSession.java:1777) ~[nifi-framework-core-0.4.0-SNAPSHOT.jar:0.4.0-SNAPSHOT]
        at org.apache.nifi.processors.standard.ExecuteStreamCommand.onTrigger(ExecuteStreamCommand.java:350) ~[na:na]
        at org.apache.nifi.processor.AbstractProcessor.onTrigger(AbstractProcessor.java:27) ~[nifi-api-0.4.0-SNAPSHOT.jar:0.4.0-SNAPSHOT]
        at org.apache.nifi.controller.StandardProcessorNode.onTrigger(StandardProcessorNode.java:1146) ~[nifi-framework-core-0.4.0-SNAPSHOT.jar:0.4.0-SNAPSHOT]
        at org.apache.nifi.controller.scheduling.EventDrivenSchedulingAgent$EventDrivenTask.trigger(EventDrivenSchedulingAgent.java:321) [nifi-framework-core-0.4.0-SNAPSHOT.jar:0.4.0-SNAPSHOT]
        at org.apache.nifi.controller.scheduling.EventDrivenSchedulingAgent$EventDrivenTask.run(EventDrivenSchedulingAgent.java:203) [nifi-framework-core-0.4.0-SNAPSHOT.jar:0.4.0-SNAPSHOT]
        at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) [na:1.8.0_60]
        at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308) [na:1.8.0_60]
        at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180) [na:1.8.0_60]
        at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294) [na:1.8.0_60]
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) [na:1.8.0_60]
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) [na:1.8.0_60]
        at java.lang.Thread.run(Thread.java:745) [na:1.8.0_60]