From 8a70596a7de680e02fb2a6db59e622a653f097c2 Mon Sep 17 00:00:00 2001
From: Thomas Munro <thomas.munro@gmail.com>
Date: Thu, 15 Dec 2022 13:38:57 +1300
Subject: [PATCH] Remove obsolete defense against strxfrm() bugs.

Old versions of Solaris and illumos had buffer overrun bugs in their
strxfrm() implementations.  The bugs were fixed a decade ago and the
relevant releases are long out of vendor support.  It's time to remove
the defense added by commit be8b06c3.

diff --git a/src/backend/main/main.c b/src/backend/main/main.c
index 37989ba567..bf6992d9fe 100644
--- a/src/backend/main/main.c
+++ b/src/backend/main/main.c
@@ -137,8 +137,6 @@ main(int argc, char *argv[])
 	 */
 	unsetenv("LC_ALL");
 
-	check_strxfrm_bug();
-
 	/*
 	 * Catch standard options before doing much else, in particular before we
 	 * insist on not being root.
diff --git a/src/backend/utils/adt/pg_locale.c b/src/backend/utils/adt/pg_locale.c
index 2b42d9ccd8..aa60008ad7 100644
--- a/src/backend/utils/adt/pg_locale.c
+++ b/src/backend/utils/adt/pg_locale.c
@@ -1134,64 +1134,6 @@ IsoLocaleName(const char *winlocname)
 #endif							/* WIN32 && LC_MESSAGES */
 
 
-/*
- * Detect aging strxfrm() implementations that, in a subset of locales, write
- * past the specified buffer length.  Affected users must update OS packages
- * before using PostgreSQL 9.5 or later.
- *
- * Assume that the bug can come and go from one postmaster startup to another
- * due to physical replication among diverse machines.  Assume that the bug's
- * presence will not change during the life of a particular postmaster.  Given
- * those assumptions, call this no less than once per postmaster startup per
- * LC_COLLATE setting used.  No known-affected system offers strxfrm_l(), so
- * there is no need to consider pg_collation locales.
- */
-void
-check_strxfrm_bug(void)
-{
-	char		buf[32];
-	const int	canary = 0x7F;
-	bool		ok = true;
-
-	/*
-	 * Given a two-byte ASCII string and length limit 7, 8 or 9, Solaris 10
-	 * 05/08 returns 18 and modifies 10 bytes.  It respects limits above or
-	 * below that range.
-	 *
-	 * The bug is present in Solaris 8 as well; it is absent in Solaris 10
-	 * 01/13 and Solaris 11.2.  Affected locales include is_IS.ISO8859-1,
-	 * en_US.UTF-8, en_US.ISO8859-1, and ru_RU.KOI8-R.  Unaffected locales
-	 * include de_DE.UTF-8, de_DE.ISO8859-1, zh_TW.UTF-8, and C.
-	 */
-	buf[7] = canary;
-	(void) strxfrm(buf, "ab", 7);
-	if (buf[7] != canary)
-		ok = false;
-
-	/*
-	 * illumos bug #1594 was present in the source tree from 2010-10-11 to
-	 * 2012-02-01.  Given an ASCII string of any length and length limit 1,
-	 * affected systems ignore the length limit and modify a number of bytes
-	 * one less than the return value.  The problem inputs for this bug do not
-	 * overlap those for the Solaris bug, hence a distinct test.
-	 *
-	 * Affected systems include smartos-20110926T021612Z.  Affected locales
-	 * include en_US.ISO8859-1 and en_US.UTF-8.  Unaffected locales include C.
-	 */
-	buf[1] = canary;
-	(void) strxfrm(buf, "a", 1);
-	if (buf[1] != canary)
-		ok = false;
-
-	if (!ok)
-		ereport(ERROR,
-				(errcode(ERRCODE_SYSTEM_ERROR),
-				 errmsg_internal("strxfrm(), in locale \"%s\", writes past the specified array length",
-								 setlocale(LC_COLLATE, NULL)),
-				 errhint("Apply system library package updates.")));
-}
-
-
 /*
  * Cache mechanism for collation information.
  *
diff --git a/src/backend/utils/init/postinit.c b/src/backend/utils/init/postinit.c
index a990c833c5..d07adb0a20 100644
--- a/src/backend/utils/init/postinit.c
+++ b/src/backend/utils/init/postinit.c
@@ -475,8 +475,6 @@ CheckMyDatabase(const char *name, bool am_superuser, bool override_allow_connect
 	SetConfigOption("lc_collate", collate, PGC_INTERNAL, PGC_S_DYNAMIC_DEFAULT);
 	SetConfigOption("lc_ctype", ctype, PGC_INTERNAL, PGC_S_DYNAMIC_DEFAULT);
 
-	check_strxfrm_bug();
-
 	ReleaseSysCache(tup);
 }
 
diff --git a/src/include/utils/pg_locale.h b/src/include/utils/pg_locale.h
index a875942123..60ccd7e34d 100644
--- a/src/include/utils/pg_locale.h
+++ b/src/include/utils/pg_locale.h
@@ -50,7 +50,6 @@ extern PGDLLIMPORT char *localized_full_months[];
 
 extern bool check_locale(int category, const char *locale, char **canonname);
 extern char *pg_perm_setlocale(int category, const char *locale);
-extern void check_strxfrm_bug(void);
 
 extern bool lc_collate_is_c(Oid collation);
 extern bool lc_ctype_is_c(Oid collation);
-- 
2.38.1