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
public static String AbstractResourcesOperation_outOfSyncError;
	public static String AbstractResourcesOperation_outOfSyncQuestion;
	public static String AbstractResourcesOperation_deletionMessageTitle;
	public static String AbstractResourcesOperation_deletionExceptionMessage;
	
	public static String AbstractCopyOrMoveResourcesOperation_SameNameOrLocation;
	public static String AbstractCopyOrMoveResourcesOperation_ResourceDoesNotExist;
	public static String AbstractCopyOrMoveResourcesOperation_ReadOnly;
	public static String AbstractCopyOrMoveResourcesOperation_copyProjectProgress;
	public static String AbstractCopyOrMoveResourcesOperation_moveProjectProgress;
	
	public static String DeleteResourcesOperation_DeletingProjectContentWarning;
	
	public static String CopyResourcesOperation_NotAllowedDueToDataLoss;
	
	public static String ProjectDescription_NewProjectProgress;
	public static String FileDescription_NewFileProgress;
	public static String FileDescription_SavingUndoInfoProgress;
	public static String FileDescription_ContentsCouldNotBeRestored;
	public static String FolderDescription_NewFolderProgress;
	public static String FolderDescription_SavingUndoInfoProgress;
	
	public static String MarkerOperation_ResourceDoesNotExist;
	public static String MarkerOperation_MarkerDoesNotExist;
	public static String MarkerOperation_NotEnoughInfo;	
	public static String MarkerOperation_CreateProgress;
	public static String MarkerOperation_DeleteProgress;
	public static String MarkerOperation_UpdateProgress;
}