From 677f74e5bb8360122ebf2f473d7169ed65ce4dba Mon Sep 17 00:00:00 2001 From: Alvaro Herrera Date: Tue, 1 Dec 2020 11:46:56 -0300 Subject: [PATCH] Avoid memcpy() with a NULL source pointer and count == 0 When memcpy() is called on a pointer, the compiler is entitled to assume that the pointer is not null, which can lead to optimizing nearby code in potentially undesirable ways. We still want such optimizations (gcc's -fdelete-null-pointer-checks) in cases where they're valid. Related: commit 13bba02271dc. Backpatch to pg11, where this particular instance appeared. Reported-by: Ranier Vilela Reported-by: Zhihong Yu Discussion: https://postgr.es/m/CAEudQApUndmQkr5fLrCKXQ7+ib44i7S+Kk93pyVThS85PnG3bQ@mail.gmail.com Discussion: https://postgr.es/m/CALNJ-vSdhwSM5f4tnNn1cdLHvXMVe_S+V3nR5GwNrmCPNB2VtQ@mail.gmail.com --- src/backend/commands/indexcmds.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c index ca24620fd0..d35deb433a 100644 --- a/src/backend/commands/indexcmds.c +++ b/src/backend/commands/indexcmds.c @@ -1163,15 +1163,17 @@ DefineIndex(Oid relationId, if (partitioned) { + PartitionDesc partdesc; + /* * Unless caller specified to skip this step (via ONLY), process each * partition to make sure they all contain a corresponding index. * * If we're called internally (no stmt->relation), recurse always. */ - if (!stmt->relation || stmt->relation->inh) + partdesc = RelationGetPartitionDesc(rel); + if ((!stmt->relation || stmt->relation->inh) && partdesc->nparts > 0) { - PartitionDesc partdesc = RelationGetPartitionDesc(rel); int nparts = partdesc->nparts; Oid *part_oids = palloc(sizeof(Oid) * nparts); bool invalidate_parent = false;