From 1cac8c98201cb0ed1a3592cf355a2670d3771689 Mon Sep 17 00:00:00 2001
From: Kevin Grittner <kgrittn@postgresql.org>
Date: Wed, 19 Aug 2015 08:20:55 -0500
Subject: [PATCH] Fix bug in calculations of hash join buckets.

Commit 8cce08f168481c5fc5be4e7e29b968e314f1b41e used a left-shift
on a literal of 1 that could (in large allocations) be shifted by
31 or more bits.  This was assigned to a local variable that was
already declared to be a long to protect against overruns of int,
but the literal in this shift needs to be declared long to allow it
to work correctly in some compilers.

Backpatch to 9.5, where the bug was introduced.

Report and patch by KaiGai Kohei, slighly modified based on
discussion.
---
 src/backend/executor/nodeHash.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/backend/executor/nodeHash.c b/src/backend/executor/nodeHash.c
index ee9298a157f..0b2c13917ee 100644
--- a/src/backend/executor/nodeHash.c
+++ b/src/backend/executor/nodeHash.c
@@ -518,7 +518,7 @@ ExecChooseHashTableSize(double ntuples, int tupwidth, bool useskew,
 		 * overhead for the hash code, pointer to the next tuple, etc.
 		 */
 		bucket_size = (tupsize * NTUP_PER_BUCKET + sizeof(HashJoinTuple));
-		lbuckets = 1 << my_log2(hash_table_bytes / bucket_size);
+		lbuckets = 1L << my_log2(hash_table_bytes / bucket_size);
 		lbuckets = Min(lbuckets, max_pointers);
 		nbuckets = (int) lbuckets;
 		bucket_bytes = nbuckets * sizeof(HashJoinTuple);
-- 
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