e4: FinishedJobs instance is never injected into ProgressServiceImpl for progress dialogs

[selundqma]

My progress monitor dialog throws a NPE when cancelling a sub job in the details view (the red button). I have traced the issue down to the ProgressServiceImpl class where the finishedJobs variable isn´t injected, thus is always null. I tried to download the code from GitHub and use it instead of the plugin in Eclipse 2024-03 (4.31) and by removing the row with @Optional, it suddenly worked just fine.

@Inject
FinishedJobs finishedJobs;

Stack trace:
java.lang.NullPointerException: Cannot invoke "org.eclipse.e4.ui.progress.internal.FinishedJobs.isKept(org.eclipse.e4.ui.progress.internal.JobTreeElement)" because "this.finishedJobs" is null
at org.eclipse.e4.ui.progress.internal.ProgressInfoItem.cancelOrRemove(ProgressInfoItem.java:308)
at org.eclipse.e4.ui.progress.internal.ProgressInfoItem$1.widgetSelected(ProgressInfoItem.java:229)
at org.eclipse.swt.widgets.TypedListener.handleEvent(TypedListener.java:252)
at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:89)
at org.eclipse.swt.widgets.Display.sendEvent(Display.java:4274)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1066)
at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:4072)
at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3660)
at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine$5.run(PartRenderingEngine.java:1151)
at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:339)
at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.run(PartRenderingEngine.java:1042)
at org.eclipse.e4.ui.internal.workbench.E4Workbench.createAndRunUI(E4Workbench.java:152)
at org.eclipse.e4.ui.internal.workbench.swt.E4Application.start(E4Application.java:165)
at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:208)
at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:143)
at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:109)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:439)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:271)
at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)
at java.base/java.lang.reflect.Method.invoke(Method.java:580)
at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:651)
at org.eclipse.equinox.launcher.Main.basicRun(Main.java:588)
at org.eclipse.equinox.launcher.Main.run(Main.java:1459)
at org.eclipse.equinox.launcher.Main.main(Main.java:1432)

I also tried to add a ProgressView to my application to get the jobs listed there. And that works just fine. Probably due to the correctly injected FinishedJobs instance in the view´s createPartControl method (which doesn´t use the @Optional annotation.

[jukzi]

@selundqma there a no active maintainers for e4. Can you provide a test & bugfix?

[selundqma]

Hi @jukzi ! Sure, the fix I proposed in the initial text should do the trick. I would have to see how to provide a test for it. Any idea what to think about there? Then.. do I have to become a Commiter in this project to be able to fork, pull, create PR and submit?

[jukzi]

Please see https://github.com/eclipse-platform/.github/blob/main/CONTRIBUTING.md
You can suggest a Pull Request without being committer. A committer may review and apply the fix. Only If you contribute regular you may be gain committer status.
Just removing @Optional may be wrong for other use cases.