Bug 162655 [Undo] [IDE] - Undoing a delete should check for existence of resources to be restored
N20061027. - I deleted two projects (along with their content). I read the warning that undo delete cannot restore the content and said "OK." - Then I checked out those same projects from HEAD. - Then I selected "Undo Delete Resources." This overwrote my code with empty projects. I think that "Undo Delete Resources" should become invalid if the resources exist again, because you'll end up replacing content without keeping a backup.
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/ide/undo/UndoMessages.java
private static final String BUNDLE_NAME = "org.eclipse.ui.internal.ide.undo.messages"; 
	static {
		
		NLS.initializeMessages(BUNDLE_NAME, UndoMessages.class);
	}
	public static String AbstractWorkspaceOperation_ExecuteErrorTitle;
	public static String AbstractWorkspaceOperation_RedoErrorTitle;
	public static String AbstractWorkspaceOperation_UndoErrorTitle;
	public static String AbstractWorkspaceOperation_SideEffectsWarningTitle;
	public static String AbstractWorkspaceOperation_ExecuteSideEffectsWarningMessage;
	public static String AbstractWorkspaceOperation_UndoSideEffectsWarningMessage;
	public static String AbstractWorkspaceOperation_RedoSideEffectsWarningMessage;
	public static String AbstractWorkspaceOperation_ErrorInvalidMessage;
	public static String AbstractWorkspaceOperation_GenericWarningMessage;
	
	public static String AbstractResourcesOperation_ResourcesDoNotExist;
	public static String AbstractResourcesOperation_NotEnoughInfo;
	public static String AbstractResourcesOperation_InvalidRestoreInfo;
	public static String AbstractResourcesOperation_DeleteResourcesProgress;
	public static String AbstractResourcesOperation_CreateResourcesProgress;
	public static String AbstractResourcesOperation_CopyingResourcesProgress;
	public static String AbstractResourcesOperation_MovingResources;