Log Message:
-----------
Make use of backup label/history files to control recovery properly.
Modified Files:
--------------
pgsql-server/src/backend/access/transam:
xlog.c (r1.154 -> r1.155)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/backend/access/transam/xlog.c.diff?r1=1.154&r2=1.155)