Bug 220697 [Undo] Exceptions when validating a delete operation
Build ID: M20071023-1652 Steps To Reproduce: It is hard to reproduce. But it happens from time to time. From our editor, when user saves the file, we write to an IFile. We get the exception shown below. We are using File.setContents(stream, true, true, progressmonitor); So we are setting keep history to true and we are using force flag. More information: Problems occurred when invoking code from plug-in: "org.eclipse.core.resources". java.lang.NullPointerException at org.eclipse.ui.ide.undo.AbstractResourcesOperation.computeCreateStatus(AbstractResourcesOperation.java:164) at org.eclipse.ui.ide.undo.DeleteResourcesOperation.computeUndoableStatus(DeleteResourcesOperation.java:156) at org.eclipse.ui.internal.ide.undo.WorkspaceUndoMonitor.checkOperationHistory(WorkspaceUndoMonitor.java:235) at org.eclipse.ui.internal.ide.undo.WorkspaceUndoMonitor.access$4(WorkspaceUndoMonitor.java:209) at org.eclipse.ui.internal.ide.undo.WorkspaceUndoMonitor$1.resourceChanged(WorkspaceUndoMonitor.java:132) at org.eclipse.core.internal.events.NotificationManager$2.run(NotificationManager.java:282) at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:37) at org.eclipse.core.internal.events.NotificationManager.notify(NotificationManager.java:276) at org.eclipse.core.internal.events.NotificationManager.broadcastChanges(NotificationManager.java:148) at org.eclipse.core.internal.resources.Workspace.broadcastPostChange(Workspace.java:311) at org.eclipse.core.internal.resources.Workspace.endOperation(Workspace.java:1018) at org.eclipse.core.internal.resources.File.setContents(File.java:363) at org.eclipse.core.internal.resources.File.setContents(File.java:458) at com.fnfr.documents.helpers.DocumentHelper.writeToDocument(DocumentHelper.java:216) at com.fnfr.documents.helpers.DocumentHelper.writeToDocument(DocumentHelper.java:223) at com.fnfr.svt.ui.common.editors.FanfareFormEditor.saveDocumentToFile(FanfareFormEditor.java:979) at com.fnfr.svt.ui.common.editors.FanfareFormEditor$5.doPersistence(FanfareFormEditor.java:810) at com.fnfr.svt.ui.common.interfaces.AbstractPersistenceDelegate.persist(AbstractPersistenceDelegate.java:34) at com.fnfr.svt.ui.common.editors.FanfareFormEditor.managePersistence(FanfareFormEditor.java:935) at com.fnfr.svt.ui.common.editors.FanfareFormEditor.doSave(FanfareFormEditor.java:830) at org.eclipse.ui.internal.SaveableHelper$1.run(SaveableHelper.java:143) at org.eclipse.ui.internal.SaveableHelper$4.run(SaveableHelper.java:266) at org.eclipse.jface.operation.ModalContext.runInCurrentThread(ModalContext.java:369) at org.eclipse.jface.operation.ModalContext.run(ModalContext.java:313) at org.eclipse.jface.window.ApplicationWindow$1.run(ApplicationWindow.java:758) at org.eclipse.swt.custom.BusyIndicator.showWhile(BusyIndicator.java:67) at org.eclipse.jface.window.ApplicationWindow.run(ApplicationWindow.java:755) at org.eclipse.ui.internal.WorkbenchWindow.run(WorkbenchWindow.java:2451) at org.eclipse.ui.internal.SaveableHelper.runProgressMonitorOperation(SaveableHelper.java:274) at org.eclipse.ui.internal.SaveableHelper.runProgressMonitorOperation(SaveableHelper.java:253) at org.eclipse.ui.internal.SaveableHelper.savePart(SaveableHelper.java:148) at org.eclipse.ui.internal.EditorManager.savePart(EditorManager.java:1345) at org.eclipse.ui.internal.WorkbenchPage.savePart(WorkbenchPage.java:3184) at org.eclipse.ui.internal.WorkbenchPage.saveEditor(WorkbenchPage.java:3197) at org.eclipse.ui.internal.SaveAction.run(SaveAction.java:73) at org.eclipse.jface.action.Action.runWithEvent(Action.java:498) at org.eclipse.jface.action.ActionContributionItem.handleWidgetSelection(ActionContributionItem.java:545) at org.eclipse.jface.action.ActionContributionItem.access$2(ActionContributionItem.java:490) at org.eclipse.jface.action.ActionContributionItem$6.handleEvent(ActionContributionItem.java:443) at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:66) at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:938) at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:3682) at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3293) at org.eclipse.ui.internal.Workbench.runEventLoop(Workbench.java:2389) at org.eclipse.ui.internal.Workbench.runUI(Workbench.java:2353) at org.eclipse.ui.internal.Workbench.access$4(Workbench.java:2219) at org.eclipse.ui.internal.Workbench$4.run(Workbench.java:466) at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:289) at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:461) at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:149) at com.fnfr.svt.rcp.Application.runWorkbench(Application.java:144) at com.fnfr.svt.rcp.Application.start(Application.java:132) at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:153) at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:106) at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:76) at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:363) at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:176) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) at java.lang.reflect.Method.invoke(Unknown Source) at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:504) at org.eclipse.equinox.launcher.Main.basicRun(Main.java:443) at org.eclipse.equinox.launcher.Main.run(Main.java:1169)
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/ide/undo/AbstractResourcesOperation.java
}
	
	/**
	 * Check the specified resources for read only state, and return a
	 * status indicating whether the resources can be deleted.  
	 */
	IStatus checkReadOnlyResources(IResource[] resourcesToCheck) {
		
		
		if (!quietCompute) {
			ReadOnlyStateChecker checker = new ReadOnlyStateChecker(
					getShell(null),
					IDEWorkbenchMessages.DeleteResourceAction_title1,
					IDEWorkbenchMessages.DeleteResourceAction_readOnlyQuestion);
			checker.setIgnoreLinkedResources(true);
			IResource[] approvedResources = checker
					.checkReadOnlyResources(resourcesToCheck);
			if (approvedResources.length == 0) {
				
				return Status.CANCEL_STATUS;
			}
			
			setTargetResources(approvedResources);
		}
		return Status.OK_STATUS;
	}
	/**
	 * Set the array of resource descriptions describing resources to be
	 * restored when undoing or redoing this operation.
	 *