Обсуждение: pgsql: Fix SQL function execution to be safe with long-lived FmgrInfos.

Fix SQL function execution to be safe with long-lived FmgrInfos.

fmgr_sql had been designed on the assumption that the FmgrInfo it's called
with has only query lifespan.  This is demonstrably unsafe in connection
with range types, as shown in bug #7881 from Andrew Gierth.  Fix things
so that we re-generate the function's cache data if the (sub)transaction
it was made in is no longer active.

Back-patch to 9.2.  This might be needed further back, but it's not clear
whether the case can realistically arise without range types, so for now
I'll desist from back-patching further.

Branch
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master

Details
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http://git.postgresql.org/pg/commitdiff/2b78d101d1d6b1d8533a7b7aeff4d82b10a915f8

Modified Files
--------------
src/backend/access/transam/xact.c |   21 +++++++++
src/backend/executor/functions.c  |   88 ++++++++++++++++++++++++++++++++-----
src/include/access/xact.h         |    1 +
3 files changed, 98 insertions(+), 12 deletions(-)