Opening the mapping stats crashes Enigma

[jordanamr]

When opening a jar, then an Enigma mappings folder and trying to view the mappings stats, it shows this instead :

java.lang.NullPointerException: Cannot invoke "String.startsWith(String)" because the return value of "cuchaz.enigma.translation.representation.entry.ClassEntry.getPackageName()" is null
    at cuchaz.enigma.gui.stats.StatsGenerator.generate(StatsGenerator.java:105)
    at cuchaz.enigma.gui.dialog.StatsDialog.lambda$show$1(StatsDialog.java:37)
    at cuchaz.enigma.gui.dialog.ProgressDialog.lambda$runOffThread$1(ProgressDialog.java:97)
    at java.base/java.util.concurrent.CompletableFuture$UniAccept.tryFire(CompletableFuture.java:718)
    at java.base/java.util.concurrent.CompletableFuture$Completion.exec(CompletableFuture.java:483)
    at java.base/java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:373)
    at java.base/java.util.concurrent.ForkJoinPool$WorkQueue.topLevelExec(ForkJoinPool.java:1182)
    at java.base/java.util.concurrent.ForkJoinPool.scan(ForkJoinPool.java:1655)
    at java.base/java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1622)
    at java.base/java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:165)

Enigma version: 2.3.1-all.jar from the repository. OS: Arch Java version: Installed from the jdk17-openjdk AUR

openjdk version "17.0.7" 2023-04-18
OpenJDK Runtime Environment (build 17.0.7+7)
OpenJDK 64-Bit Server VM (build 17.0.7+7, mixed mode)

[jordanamr]

FYI iy also happens while simply opening the jar and trying to see stats without any mappings opened. I'm providing the jar in question in a zip file core.zip

[mudkipdev]

The null pointer exception still occurs, only on line 70 this time. I attempted to fix it in #504.