Log Message:
-----------
Prevent RevalidateCachedPlan from making any permanent change in
ActiveSnapshot. Having it affect ActiveSnapshot only in the unusual
case of needing to replan seems a bad idea, and there's also the problem
that the created snap might be in a relatively short-lived context, as
noted by Jan Wieck. Also, there's no need to force a new snap at all
unless we are called with no snap currently set, which is an unusual
case in itself.
Modified Files:
--------------
pgsql/src/backend/utils/cache:
plancache.c (r1.8 -> r1.9)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/cache/plancache.c.diff?r1=1.8&r2=1.9)
