NPE when opening grammar preferences

[mtheiss]

Selecting a grammar in the preferences fails with a NPE.

Features:
TextMate Core 0.5.2.202210241440 org.eclipse.tm4e.feature.feature.group Eclipse TM4E

Plugins:
Eclipse TM4E TextMate support in Eclipse IDE - UI 0.6.1.202210221922 org.eclipse.tm4e.ui

Stacktrace:

java.lang.NullPointerException: Cannot invoke "org.eclipse.swt.widgets.Button.setEnabled(boolean)" because the return value of "org.eclipse.tm4e.ui.internal.widgets.ThemeAssociationsWidget.getNewButton()" is null
	at org.eclipse.tm4e.ui.internal.preferences.GrammarPreferencePage$1.selectionChanged(GrammarPreferencePage.java:244)
	at org.eclipse.jface.viewers.Viewer$1.run(Viewer.java:151)
	at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:45)
	at org.eclipse.jface.util.SafeRunnable.run(SafeRunnable.java:174)
	at org.eclipse.jface.viewers.Viewer.fireSelectionChanged(Viewer.java:148)
	at org.eclipse.jface.viewers.StructuredViewer.updateSelection(StructuredViewer.java:2128)
	at org.eclipse.jface.viewers.StructuredViewer.handleSelect(StructuredViewer.java:1176)
	at org.eclipse.jface.viewers.StructuredViewer$4.widgetSelected(StructuredViewer.java:1205)
	at org.eclipse.jface.util.OpenStrategy.fireSelectionEvent(OpenStrategy.java:263)
	at org.eclipse.jface.util.OpenStrategy$1.handleEvent(OpenStrategy.java:421)
	at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:89)
	at org.eclipse.swt.widgets.Display.sendEvent(Display.java:4251)
	at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1066)
	at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:4068)
	at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3645)
	at org.eclipse.jface.window.Window.runEventLoop(Window.java:823)
	at org.eclipse.jface.window.Window.open(Window.java:799)
	at org.eclipse.ui.internal.OpenPreferencesAction.run(OpenPreferencesAction.java:66)
	at org.eclipse.jface.action.Action.runWithEvent(Action.java:474)
	at org.eclipse.jface.action.ActionContributionItem.handleWidgetSelection(ActionContributionItem.java:580)
	at org.eclipse.jface.action.ActionContributionItem.lambda$4(ActionContributionItem.java:414)
	at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:89)
	at org.eclipse.swt.widgets.Display.sendEvent(Display.java:4251)
	at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1066)
	at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:4068)
	at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3645)
	at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine$5.run(PartRenderingEngine.java:1155)
	at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:338)
	at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.run(PartRenderingEngine.java:1046)
	at org.eclipse.e4.ui.internal.workbench.E4Workbench.createAndRunUI(E4Workbench.java:155)
	at org.eclipse.ui.internal.Workbench.lambda$3(Workbench.java:643)
	at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:338)
	at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:550)
	at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:171)
	at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:152)
	at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:203)
	at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:136)
	at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:104)
	at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:402)
	at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:255)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.base/java.lang.reflect.Method.invoke(Method.java:568)
	at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:659)
	at org.eclipse.equinox.launcher.Main.basicRun(Main.java:596)
	at org.eclipse.equinox.launcher.Main.run(Main.java:1467)

[akurtakov]

Could you please share exact steps and some more details as I'm not able to reproduce it locally?

[mtheiss]

• Install a fresh Eclipse IDE for Enterprise Java and Web Developers (2022-09)
• Install from https://download.eclipse.org/tm4e/snapshots/ the the features
  TextMate Core 0.5.2.202211011245
  TextMate Language Pack 0.1.1.202210101209
• Restart IDE
• Navigate to Window/Preferences/TextMate/Grammar
• Click on any Grammar entry