Small typo in timeline.h regarding the meaning of infinity for timeline history entry

Hi all,

timeline.h quotes that the end point of timeline history entry means
infinity when its value is 0. But that's not completely true, I think
that what is meant here is InvalidXLogRecPtr:
 {
        TimeLineID      tli;
        XLogRecPtr      begin;                  /* inclusive */
-       XLogRecPtr      end;                    /* exclusive, 0 means
infinity */
+       XLogRecPtr      end;                    /* exclusive,
InvalidXLogRecPtr means
+                                                                * infinity */
 } TimeLineHistoryEntry;

And the code leads into this direction as well.
Regards,
--
Michael