inplace type hierarchy throws exception in 2025-03

[martinlippert]

I am using Eclipse JEE package 2025-03 M2. Created a simple plain Java 21 project, created one empty class.
Java editor is open, then invoking the inplace type hierarchy popup (Cmd-T on macOS). That works. Pressing CMd-T again to switch the mode doesn't work and throws tons of exception in the Error Log instead:

java.lang.NullPointerException: Cannot invoke "java.util.Set.add(Object)" because "this.visited" is null
	at org.eclipse.jdt.internal.ui.typehierarchy.HierarchyInformationControl$2.shouldExpand(HierarchyInformationControl.java:159)
	at org.eclipse.jdt.internal.ui.typehierarchy.HierarchyInformationControl$2.internalExpandToLevel(HierarchyInformationControl.java:148)
	at org.eclipse.jface.viewers.AbstractTreeViewer.expandToLevel(AbstractTreeViewer.java:1166)
	at org.eclipse.jface.viewers.AbstractTreeViewer.lambda$1(AbstractTreeViewer.java:1123)
	at org.eclipse.swt.custom.BusyIndicator.showWhile(BusyIndicator.java:67)
	at org.eclipse.jface.viewers.AbstractTreeViewer.expandToLevel(AbstractTreeViewer.java:1123)
	at org.eclipse.jface.viewers.AbstractTreeViewer.expandAll(AbstractTreeViewer.java:1084)
	at org.eclipse.jdt.internal.ui.typehierarchy.HierarchyInformationControl.toggleHierarchy(HierarchyInformationControl.java:364)
	at org.eclipse.jdt.internal.ui.typehierarchy.HierarchyInformationControl$1.keyPressed(HierarchyInformationControl.java:105)
	at org.eclipse.swt.widgets.TypedListener.handleEvent(TypedListener.java:205)
	at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:91)
	at org.eclipse.swt.widgets.Display.sendEvent(Display.java:4660)
	at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1657)
	at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1680)
	at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1665)
	at org.eclipse.swt.widgets.Widget.sendKeyEvent(Widget.java:1694)
	at org.eclipse.swt.widgets.Text.sendKeyEvent(Text.java:1753)
	at org.eclipse.swt.widgets.Widget.sendKeyEvent(Widget.java:1690)
	at org.eclipse.swt.widgets.Text.sendKeyEvent(Text.java:1718)
	at org.eclipse.swt.widgets.Control.doCommandBySelector(Control.java:1052)
	at org.eclipse.swt.widgets.Display.windowProc(Display.java:6443)
	at org.eclipse.swt.internal.cocoa.OS.objc_msgSendSuper(Native Method)
	at org.eclipse.swt.widgets.Widget.callSuper(Widget.java:239)
	at org.eclipse.swt.widgets.Widget.superKeyDown(Widget.java:2217)
	at org.eclipse.swt.widgets.Widget.keyDown(Widget.java:1200)
	at org.eclipse.swt.widgets.Control.keyDown(Control.java:2425)
	at org.eclipse.swt.widgets.Display.windowProc(Display.java:6289)
	at org.eclipse.swt.internal.cocoa.OS.objc_msgSendSuper(Native Method)
	at org.eclipse.swt.widgets.Widget.callSuper(Widget.java:239)
	at org.eclipse.swt.widgets.Widget.windowSendEvent(Widget.java:2407)
	at org.eclipse.swt.widgets.Shell.windowSendEvent(Shell.java:2502)
	at org.eclipse.swt.widgets.Display.windowProc(Display.java:6401)
	at org.eclipse.swt.internal.cocoa.OS.objc_msgSendSuper(Native Method)
	at org.eclipse.swt.widgets.Display.applicationSendEvent(Display.java:5705)
	at org.eclipse.swt.widgets.Display.applicationProc(Display.java:5845)
	at org.eclipse.swt.internal.cocoa.OS.objc_msgSend(Native Method)
	at org.eclipse.swt.internal.cocoa.NSApplication.sendEvent(NSApplication.java:117)
	at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:4000)
	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:153)
	at org.eclipse.ui.internal.Workbench.lambda$3(Workbench.java:665)
	at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:339)
	at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:573)
	at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:173)
	at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:178)
	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:668)
	at org.eclipse.equinox.launcher.Main.basicRun(Main.java:605)
	at org.eclipse.equinox.launcher.Main.run(Main.java:1481)

[jukzi]

regression from a17cf63, @fedejeanne please take a look

[jukzi]

Probably AbstractTreeViewer#expandToLevel needs a override too

[fedejeanne]

I will look into it, thank you for the heads up.