pgsql: Correctly detect SSI conflicts of prepared transactions after cr

Correctly detect SSI conflicts of prepared transactions after crash.

A prepared transaction can get new conflicts in and out after preparing, so
we cannot rely on the in- and out-flags stored in the statefile at prepare-
time. As a quick fix, make the conservative assumption that after a restart,
all prepared transactions are considered to have both in- and out-conflicts.
That can lead to unnecessary rollbacks after a crash, but that shouldn't be
a big problem in practice; you don't want prepared transactions to hang
around for a long time anyway.

Dan Ports

Branch
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REL9_1_STABLE

Details
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http://git.postgresql.org/pg/commitdiff/86073a2b7acc58fce8701a9207a46adb41fbd8cc

Modified Files
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src/backend/storage/lmgr/predicate.c | 31 +++++++++++++++----------------
1 files changed, 15 insertions(+), 16 deletions(-)