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| author | Tom Lane <tgl@sss.pgh.pa.us> | 2016-06-05 11:53:06 -0400 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2016-06-05 11:53:06 -0400 |
| commit | a7aa61ffe7ed12cf8d5cbdfc887900549f9ed354 (patch) | |
| tree | c889756c49dbbb62c50727f5257049b3591530fb /src/backend/executor | |
| parent | c82037e372394ee046e278887c8f938591ca7406 (diff) | |
| download | postgresql-a7aa61ffe7ed12cf8d5cbdfc887900549f9ed354.tar.gz postgresql-a7aa61ffe7ed12cf8d5cbdfc887900549f9ed354.zip | |
Properly initialize SortSupport for ORDER BY rechecks in nodeIndexscan.c.
Fix still another bug in commit 35fcb1b3d: it failed to fully initialize
the SortSupport states it introduced to allow the executor to re-check
ORDER BY expressions containing distance operators. That led to a null
pointer dereference if the sortsupport code tried to use ssup_cxt. The
problem only manifests in narrow cases, explaining the lack of previous
field reports. It requires a GiST-indexable distance operator that lacks
SortSupport and is on a pass-by-ref data type, which among core+contrib
seems to be only btree_gist's interval opclass; and it requires the scan
to be done as an IndexScan not an IndexOnlyScan, which explains how
btree_gist's regression test didn't catch it. Per bug #14134 from
Jihyun Yu.
Peter Geoghegan
Report: <20160511154904.2603.43889@wrigleys.postgresql.org>
Diffstat (limited to 'src/backend/executor')
| -rw-r--r-- | src/backend/executor/nodeIndexscan.c | 15 |
1 files changed, 13 insertions, 2 deletions
diff --git a/src/backend/executor/nodeIndexscan.c b/src/backend/executor/nodeIndexscan.c index c0f14dbfa9d..11de6f11298 100644 --- a/src/backend/executor/nodeIndexscan.c +++ b/src/backend/executor/nodeIndexscan.c @@ -966,9 +966,20 @@ ExecInitIndexScan(IndexScan *node, EState *estate, int eflags) Oid orderbyop = lfirst_oid(lco); Node *orderbyexpr = (Node *) lfirst(lcx); Oid orderbyType = exprType(orderbyexpr); + Oid orderbyColl = exprCollation(orderbyexpr); + SortSupport orderbysort = &indexstate->iss_SortSupport[i]; + + /* Initialize sort support */ + orderbysort->ssup_cxt = CurrentMemoryContext; + orderbysort->ssup_collation = orderbyColl; + /* See cmp_orderbyvals() comments on NULLS LAST */ + orderbysort->ssup_nulls_first = false; + /* ssup_attno is unused here and elsewhere */ + orderbysort->ssup_attno = 0; + /* No abbreviation */ + orderbysort->abbreviate = false; + PrepareSortSupportFromOrderingOp(orderbyop, orderbysort); - PrepareSortSupportFromOrderingOp(orderbyop, - &indexstate->iss_SortSupport[i]); get_typlenbyval(orderbyType, &indexstate->iss_OrderByTypLens[i], &indexstate->iss_OrderByTypByVals[i]); |