Database export gets stuck in "4/4 Writing to file" (uncaughtException / NoSuchElementException)

[mirenbz]

Data export gets stuck in "Writing to file" with this settings:

Have tried a different save location, reloading the app, rebooting the computer... nothing seems to work.

The error logs throw this message:

    <event>
      <date>26.06.2023 23:42:28.949</date>
      <priority>3</priority>
      <coder>1</coder>
      <summary>Uncaught exception.</summary>
      <details>An uncaught exception occurred. This is most likely a bug. Please open a new issue at https://github.com/leifeld/dna/issues/ and paste the log event stack trace and the exception stack trace there as part of your error description, along with details of what happened and under what circumstances. Thank you.</details>
      <stackLog>logger.LogEvent
            at dna.Dna$DefaultExceptionHandler.uncaughtException(Dna.java:96)
            at java.base/java.lang.ThreadGroup.uncaughtException(ThreadGroup.java:1082)
            at java.base/java.lang.ThreadGroup.uncaughtException(ThreadGroup.java:1077)
            at java.base/java.lang.Thread.dispatchUncaughtException(Thread.java:2008)
      </stackLog>
      <stackException>java.util.NoSuchElementException: No value present
            at java.base/java.util.OptionalInt.getAsInt(OptionalInt.java:130)
            at export.Exporter.exportGraphml(Exporter.java:2112)
            at export.Exporter.exportToFile(Exporter.java:1891)
            at gui.NetworkExporter$GuiExportThread.run(NetworkExporter.java:1237)
            at java.base/java.lang.Thread.run(Thread.java:833)
      </stackException>
    </event>

Software version is 3.0.10, 2023-03-01.

@leifeld helped narrow this down to Variable 1 being set to author; it turns out that I really was after person here, not author... so this fixes it for me, but might still be a problem for anyone needing to work with author in there.

Thanks for all the work, and the help!