NPE when compile_commands.json changes and editor is closed

[ghentschke]

When the compile_commands.json changes and the C/C Editor (LSP) editor(s) has/have been closed until the refreshEditor has been scheduled after 5 seconds, a NPE occurs in org.eclipse.cdt.lsp.editor.ui.clangd.CompileCommandsMonitor:

!ENTRY org.eclipse.ui.workbench 4 0 2023-03-09 08:40:33.280
!MESSAGE An internal error has occurred.
!STACK 0
java.lang.NullPointerException: Cannot invoke "org.eclipse.jface.text.IDocument.getLineInformation(int)" because the return value of "org.eclipse.jface.text.TextViewer.getDocument()" is null
	at org.eclipse.jface.text.TextViewer.getBottomIndexEndOffset(TextViewer.java:3155)
	at org.eclipse.cdt.lsp.editor.ui.clangd.CompileCommandsMonitor.lambda$0(CompileCommandsMonitor.java:137)
	at org.eclipse.ui.progress.UIJob$2.runInUIThread(UIJob.java:76)
	at org.eclipse.ui.progress.UIJob.lambda$0(UIJob.java:148)
	at org.eclipse.swt.widgets.RunnableLock.run(RunnableLock.java:40)
	at org.eclipse.swt.widgets.Synchronizer.runAsyncMessages(Synchronizer.java:132)
	at org.eclipse.swt.widgets.Display.runAsyncMessages(Display.java:4029)
	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)
	at org.eclipse.equinox.launcher.Main.main(Main.java:1440)