0001-Ensure-comparison-functions-are-transitive.patch

From 83e2f14ab259f568034b07c2f99e34c6dff2c7b5 Mon Sep 17 00:00:00 2001
From: Mats Kindahl <mats@timescale.com>
Date: Tue, 6 Feb 2024 14:53:53 +0100
Subject: Ensure comparison functions are transitive

There are a few comparison functions to qsort() that are non-transitive
because they can cause an overflow. Fix these functions to instead use
normal comparisons and return -1, 0, or 1 explicitly.
---
 src/backend/access/spgist/spgtextproc.c |  6 +++++-
 src/backend/utils/cache/relcache.c      |  2 ++
 src/bin/pg_upgrade/function.c           | 10 +++++++---
 src/bin/psql/crosstabview.c             |  8 +++++++-
 4 files changed, 21 insertions(+), 5 deletions(-)

diff --git a/src/backend/access/spgist/spgtextproc.c b/src/backend/access/spgist/spgtextproc.c
index b8fd0c2ad8..d0a2b4e6e1 100644
--- a/src/backend/access/spgist/spgtextproc.c
+++ b/src/backend/access/spgist/spgtextproc.c
@@ -325,7 +325,11 @@ cmpNodePtr(const void *a, const void *b)
 	const spgNodePtr *aa = (const spgNodePtr *) a;
 	const spgNodePtr *bb = (const spgNodePtr *) b;
 
-	return aa->c - bb->c;
+	if (aa->c > bb->c)
+		return 1;
+	if (aa->c < bb->c)
+		return -1;
+	return 0;
 }
 
 Datum
diff --git a/src/backend/utils/cache/relcache.c b/src/backend/utils/cache/relcache.c
index ac106b40e3..42e4359c7b 100644
--- a/src/backend/utils/cache/relcache.c
+++ b/src/backend/utils/cache/relcache.c
@@ -4520,6 +4520,8 @@ AttrDefaultCmp(const void *a, const void *b)
 	const AttrDefault *ada = (const AttrDefault *) a;
 	const AttrDefault *adb = (const AttrDefault *) b;
 
+	/* Cannot overflow because standard conversions will convert to int and
+	 * sizeof(int16) < sizeof(int) */
 	return ada->adnum - adb->adnum;
 }
 
diff --git a/src/bin/pg_upgrade/function.c b/src/bin/pg_upgrade/function.c
index af998f74d3..c82ae11016 100644
--- a/src/bin/pg_upgrade/function.c
+++ b/src/bin/pg_upgrade/function.c
@@ -32,14 +32,18 @@ library_name_compare(const void *p1, const void *p2)
 	int			slen1 = strlen(str1);
 	int			slen2 = strlen(str2);
 	int			cmp = strcmp(str1, str2);
+	int lhsdb = ((const LibraryInfo *) p1)->dbnum;
+	int rhsdb = ((const LibraryInfo *) p2)->dbnum;
 
 	if (slen1 != slen2)
 		return slen1 - slen2;
 	if (cmp != 0)
 		return cmp;
-	else
-		return ((const LibraryInfo *) p1)->dbnum -
-			((const LibraryInfo *) p2)->dbnum;
+	if (lhsdb < rhsdb)
+		return -1;
+	if (lhsdb > rhsdb)
+		return 1;
+	return 0;
 }
 
 
diff --git a/src/bin/psql/crosstabview.c b/src/bin/psql/crosstabview.c
index c6116b7238..948ed9b1fe 100644
--- a/src/bin/psql/crosstabview.c
+++ b/src/bin/psql/crosstabview.c
@@ -709,5 +709,11 @@ pivotFieldCompare(const void *a, const void *b)
 static int
 rankCompare(const void *a, const void *b)
 {
-	return *((const int *) a) - *((const int *) b);
+	const int lhs = *(const int *) a;
+	const int rhs = *(const int *) b;
+	if (lhs < rhs)
+		return -1;
+	if (lhs > rhs)
+		return 1;
+	return 0;
 }
-- 
2.34.1