Issue #496: com.objectdb.o.InternalException NPE

[ObjectDB 2.2.9_10] Unexpected exception (Error 990)
  Generated by Java HotSpot(TM) 64-Bit Server VM 1.7.0 (on Windows 7 6.1).
Please report this error on http://www.objectdb.com/database/issue/new
com.objectdb.o.InternalException: java.lang.NullPointerException: null
java.lang.NullPointerException
at com.objectdb.o.REG.S(REG.java:822)
at com.objectdb.o.VAR.ap(VAR.java:731)
at com.objectdb.o.XQI.Vf(XQI.java:69)
at com.objectdb.o.TQI.Vf(TQI.java:67)
at com.objectdb.o.TQI.Vf(TQI.java:67)
at com.objectdb.o.TQI.Vf(TQI.java:67)
at com.objectdb.o.MQI.Vf(MQI.java:143)
at com.objectdb.o.MQI.Vf(MQI.java:120)
at com.objectdb.o.MQI.Vf(MQI.java:120)
at com.objectdb.o.SQI.Ut(SQI.java:118)
at com.objectdb.o.PRG.ab(PRG.java:603)
at com.objectdb.o.QRM.US(QRM.java:259)
at com.objectdb.o.MST.US(MST.java:895)
at com.objectdb.o.WRA.US(WRA.java:286)
at com.objectdb.o.WSM.US(WSM.java:113)
at com.objectdb.o.QRR.g(QRR.java:225)
at com.objectdb.o.QRR.b(QRR.java:144)
at com.objectdb.jpa.JpaQuery.getResultList(JpaQuery.java:635)
at com.vaisala.jx.db.gdm.facade.DataValueFacade.find(DataValueFacade.java:434)
at com.vaisala.jx.db.gdm.facade.DataValueFacadeTest.testFindDataValuesBbox2(DataValueFacadeTest.java:145)

doesn't seem to be related to build _10 or Java 1.7:

[ObjectDB 2.2.9_08] Unexpected exception (Error 990)
  Generated by Java HotSpot(TM) 64-Bit Server VM 1.6.0_24 (on Windows 7 6.1).
Please report this error on http://www.objectdb.com/database/issue/new
com.objectdb.o.InternalException: java.lang.NullPointerException: null
java.lang.NullPointerException
at com.objectdb.o.REG.S(REG.java:822)

The stack trace indicates navigation through a broken reference (probably a reference to a deleted object) during query execution.

Please check your database file using the ObjectDB Doctor.

Build 2.2.9_11 includes an attempt to avoid a NullPointerException in this case.