8 files changed, 140 insertions, 28 deletions
diff --git a/.abi-compliance-history b/.abi-compliance-history
index 6e84b96d851..4b94ea25f08 100644
--- a/.abi-compliance-history
+++ b/.abi-compliance-history
@@ -18,6 +18,14 @@
 # Be sure to replace "<ADD JUSTIFICATION HERE>" with details of your change and
 # why it is deemed acceptable.
 
+bae8ca82fd00603ebafa0658640d6e4dfe20af92
+#
+# Revisit cosmetics of "For inplace update, send nontransactional invalidations."
+# 2025-12-15 12:19:53 -0800
+#
+# This removed a CacheInvalidateHeapTupleInplace() parameter.  PGXN contained
+# no calls to that function.
+
 00eb646ea43410e5df77fed96f4a981e66811796
 #
 # Check for CREATE privilege on the schema in CREATE STATISTICS.
diff --git a/contrib/ltree/crc32.c b/contrib/ltree/crc32.c
index 134f46a805e..ce1b0f28e21 100644
--- a/contrib/ltree/crc32.c
+++ b/contrib/ltree/crc32.c
@@ -10,31 +10,62 @@
 #include "postgres.h"
 #include "ltree.h"
 
+#include "crc32.h"
+#include "utils/pg_crc.h"
 #ifdef LOWER_NODE
-#include <ctype.h>
-#define TOLOWER(x)	tolower((unsigned char) (x))
-#else
-#define TOLOWER(x)	(x)
+#include "catalog/pg_collation.h"
+#include "utils/pg_locale.h"
 #endif
 
-#include "crc32.h"
-#include "utils/pg_crc.h"
+#ifdef LOWER_NODE
 
 unsigned int
 ltree_crc32_sz(const char *buf, int size)
 {
 	pg_crc32	crc;
 	const char *p = buf;
+	static pg_locale_t locale = NULL;
+
+	if (!locale)
+		locale = pg_newlocale_from_collation(DEFAULT_COLLATION_OID);
 
 	INIT_TRADITIONAL_CRC32(crc);
 	while (size > 0)
 	{
-		char		c = (char) TOLOWER(*p);
+		char		foldstr[UNICODE_CASEMAP_BUFSZ];
+		int			srclen = pg_mblen(p);
+		size_t		foldlen;
+
+		/* fold one codepoint at a time */
+		foldlen = pg_strfold(foldstr, UNICODE_CASEMAP_BUFSZ, p, srclen,
+							 locale);
+
+		COMP_TRADITIONAL_CRC32(crc, foldstr, foldlen);
+
+		size -= srclen;
+		p += srclen;
+	}
+	FIN_TRADITIONAL_CRC32(crc);
+	return (unsigned int) crc;
+}
+
+#else
 
-		COMP_TRADITIONAL_CRC32(crc, &c, 1);
+unsigned int
+ltree_crc32_sz(const char *buf, int size)
+{
+	pg_crc32	crc;
+	const char *p = buf;
+
+	INIT_TRADITIONAL_CRC32(crc);
+	while (size > 0)
+	{
+		COMP_TRADITIONAL_CRC32(crc, p, 1);
 		size--;
 		p++;
 	}
 	FIN_TRADITIONAL_CRC32(crc);
 	return (unsigned int) crc;
 }
+
+#endif							/* !LOWER_NODE */
diff --git a/contrib/ltree/lquery_op.c b/contrib/ltree/lquery_op.c
index a6466f575fd..9b1de101213 100644
--- a/contrib/ltree/lquery_op.c
+++ b/contrib/ltree/lquery_op.c
@@ -41,7 +41,8 @@ getlexeme(char *start, char *end, int *len)
 }
 
 bool
-compare_subnode(ltree_level *t, char *qn, int len, int (*cmpptr) (const char *, const char *, size_t), bool anyend)
+compare_subnode(ltree_level *t, char *qn, int len,
+				ltree_prefix_eq_func prefix_eq, bool anyend)
 {
 	char	   *endt = t->name + t->len;
 	char	   *endq = qn + len;
@@ -57,7 +58,7 @@ compare_subnode(ltree_level *t, char *qn, int len, int (*cmpptr) (const char *,
 		while ((tn = getlexeme(tn, endt, &lent)) != NULL)
 		{
 			if ((lent == lenq || (lent > lenq && anyend)) &&
-				(*cmpptr) (qn, tn, lenq) == 0)
+				(*prefix_eq) (qn, lenq, tn, lent))
 			{
 
 				isok = true;
@@ -74,14 +75,62 @@ compare_subnode(ltree_level *t, char *qn, int len, int (*cmpptr) (const char *,
 	return true;
 }
 
-int
-ltree_strncasecmp(const char *a, const char *b, size_t s)
+/*
+ * Check if 'a' is a prefix of 'b'.
+ */
+bool
+ltree_prefix_eq(const char *a, size_t a_sz, const char *b, size_t b_sz)
+{
+	if (a_sz > b_sz)
+		return false;
+	else
+		return (strncmp(a, b, a_sz) == 0);
+}
+
+/*
+ * Case-insensitive check if 'a' is a prefix of 'b'.
+ */
+bool
+ltree_prefix_eq_ci(const char *a, size_t a_sz, const char *b, size_t b_sz)
 {
-	char	   *al = str_tolower(a, s, DEFAULT_COLLATION_OID);
-	char	   *bl = str_tolower(b, s, DEFAULT_COLLATION_OID);
-	int			res;
+	static pg_locale_t locale = NULL;
+	size_t		al_sz = a_sz + 1;
+	size_t		al_len;
+	char	   *al = palloc(al_sz);
+	size_t		bl_sz = b_sz + 1;
+	size_t		bl_len;
+	char	   *bl = palloc(bl_sz);
+	bool		res;
+
+	if (!locale)
+		locale = pg_newlocale_from_collation(DEFAULT_COLLATION_OID);
+
+	/* casefold both a and b */
+
+	al_len = pg_strfold(al, al_sz, a, a_sz, locale);
+	if (al_len + 1 > al_sz)
+	{
+		/* grow buffer if needed and retry */
+		al_sz = al_len + 1;
+		al = repalloc(al, al_sz);
+		al_len = pg_strfold(al, al_sz, a, a_sz, locale);
+		Assert(al_len + 1 <= al_sz);
+	}
+
+	bl_len = pg_strfold(bl, bl_sz, b, b_sz, locale);
+	if (bl_len + 1 > bl_sz)
+	{
+		/* grow buffer if needed and retry */
+		bl_sz = bl_len + 1;
+		bl = repalloc(bl, bl_sz);
+		bl_len = pg_strfold(bl, bl_sz, b, b_sz, locale);
+		Assert(bl_len + 1 <= bl_sz);
+	}
 
-	res = strncmp(al, bl, s);
+	if (al_len > bl_len)
+		res = false;
+	else
+		res = (strncmp(al, bl, al_len) == 0);
 
 	pfree(al);
 	pfree(bl);
@@ -109,19 +158,19 @@ checkLevel(lquery_level *curq, ltree_level *curt)
 
 	for (int i = 0; i < curq->numvar; i++)
 	{
-		int			(*cmpptr) (const char *, const char *, size_t);
+		ltree_prefix_eq_func prefix_eq;
 
-		cmpptr = (curvar->flag & LVAR_INCASE) ? ltree_strncasecmp : strncmp;
+		prefix_eq = (curvar->flag & LVAR_INCASE) ? ltree_prefix_eq_ci : ltree_prefix_eq;
 
 		if (curvar->flag & LVAR_SUBLEXEME)
 		{
-			if (compare_subnode(curt, curvar->name, curvar->len, cmpptr,
+			if (compare_subnode(curt, curvar->name, curvar->len, prefix_eq,
 								(curvar->flag & LVAR_ANYEND)))
 				return success;
 		}
 		else if ((curvar->len == curt->len ||
 				  (curt->len > curvar->len && (curvar->flag & LVAR_ANYEND))) &&
-				 (*cmpptr) (curvar->name, curt->name, curvar->len) == 0)
+				 (*prefix_eq) (curvar->name, curvar->len, curt->name, curt->len))
 			return success;
 
 		curvar = LVAR_NEXT(curvar);
diff --git a/contrib/ltree/ltree.h b/contrib/ltree/ltree.h
index 5e0761641d3..78478dec173 100644
--- a/contrib/ltree/ltree.h
+++ b/contrib/ltree/ltree.h
@@ -157,6 +157,8 @@ typedef struct
 	char		data[FLEXIBLE_ARRAY_MEMBER];
 } ltxtquery;
 
+typedef bool (*ltree_prefix_eq_func) (const char *, size_t, const char *, size_t);
+
 #define HDRSIZEQT		MAXALIGN(VARHDRSZ + sizeof(int32))
 #define COMPUTESIZE(size,lenofoperand)	( HDRSIZEQT + (size) * sizeof(ITEM) + (lenofoperand) )
 #define LTXTQUERY_TOO_BIG(size,lenofoperand) \
@@ -208,9 +210,10 @@ bool		ltree_execute(ITEM *curitem, void *checkval,
 int			ltree_compare(const ltree *a, const ltree *b);
 bool		inner_isparent(const ltree *c, const ltree *p);
 bool		compare_subnode(ltree_level *t, char *qn, int len,
-							int (*cmpptr) (const char *, const char *, size_t), bool anyend);
+							ltree_prefix_eq_func prefix_eq, bool anyend);
 ltree	   *lca_inner(ltree **a, int len);
-int			ltree_strncasecmp(const char *a, const char *b, size_t s);
+bool		ltree_prefix_eq(const char *a, size_t a_sz, const char *b, size_t b_sz);
+bool		ltree_prefix_eq_ci(const char *a, size_t a_sz, const char *b, size_t b_sz);
 
 /* fmgr macros for ltree objects */
 #define DatumGetLtreeP(X)			((ltree *) PG_DETOAST_DATUM(X))
diff --git a/contrib/ltree/ltxtquery_op.c b/contrib/ltree/ltxtquery_op.c
index 002102c9c75..3dcbab2c484 100644
--- a/contrib/ltree/ltxtquery_op.c
+++ b/contrib/ltree/ltxtquery_op.c
@@ -58,19 +58,19 @@ checkcondition_str(void *checkval, ITEM *val)
 	ltree_level *level = LTREE_FIRST(((CHKVAL *) checkval)->node);
 	int			tlen = ((CHKVAL *) checkval)->node->numlevel;
 	char	   *op = ((CHKVAL *) checkval)->operand + val->distance;
-	int			(*cmpptr) (const char *, const char *, size_t);
+	ltree_prefix_eq_func prefix_eq;
 
-	cmpptr = (val->flag & LVAR_INCASE) ? ltree_strncasecmp : strncmp;
+	prefix_eq = (val->flag & LVAR_INCASE) ? ltree_prefix_eq_ci : ltree_prefix_eq;
 	while (tlen > 0)
 	{
 		if (val->flag & LVAR_SUBLEXEME)
 		{
-			if (compare_subnode(level, op, val->length, cmpptr, (val->flag & LVAR_ANYEND)))
+			if (compare_subnode(level, op, val->length, prefix_eq, (val->flag & LVAR_ANYEND)))
 				return true;
 		}
 		else if ((val->length == level->len ||
 				  (level->len > val->length && (val->flag & LVAR_ANYEND))) &&
-				 (*cmpptr) (op, level->name, val->length) == 0)
+				 (*prefix_eq) (op, val->length, level->name, level->len))
 			return true;
 
 		tlen--;
diff --git a/doc/src/sgml/gist.sgml b/doc/src/sgml/gist.sgml
index ee86e170055..423f691dd42 100644
--- a/doc/src/sgml/gist.sgml
+++ b/doc/src/sgml/gist.sgml
@@ -291,7 +291,7 @@ CREATE INDEX ON my_table USING GIST (my_inet_column inet_ops);
    speed up building a <acronym>GiST</acronym> index.
    The optional twelfth method <function>stratnum</function> is used to
    translate compare types (from
-   <filename>src/include/nodes/primnodes.h</filename>) into strategy numbers
+   <filename>src/include/access/cmptype.h</filename>) into strategy numbers
    used by the operator class.  This lets the core code look up operators for
    temporal constraint indexes.
  </para>
@@ -1174,7 +1174,7 @@ my_sortsupport(PG_FUNCTION_ARGS)
      <listitem>
       <para>
        Given a <literal>CompareType</literal> value from
-       <filename>src/include/nodes/primnodes.h</filename>, returns a strategy
+       <filename>src/include/access/cmptype.h</filename>, returns a strategy
        number used by this operator class for matching functionality.  The
        function should return <literal>InvalidStrategy</literal> if the
        operator class has no matching strategy.
diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 94db1ec3012..5e6d21969e1 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -507,8 +507,12 @@ InitializeParallelDSM(ParallelContext *pcxt)
 void
 ReinitializeParallelDSM(ParallelContext *pcxt)
 {
+	MemoryContext oldcontext;
 	FixedParallelState *fps;
 
+	/* We might be running in a very short-lived memory context. */
+	oldcontext = MemoryContextSwitchTo(TopTransactionContext);
+
 	/* Wait for any old workers to exit. */
 	if (pcxt->nworkers_launched > 0)
 	{
@@ -546,6 +550,9 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 			pcxt->worker[i].error_mqh = shm_mq_attach(mq, pcxt->seg, NULL);
 		}
 	}
+
+	/* Restore previous memory context. */
+	MemoryContextSwitchTo(oldcontext);
 }
 
 /*
diff --git a/src/include/utils/pg_locale.h b/src/include/utils/pg_locale.h
index 953e185f92d..3a758256591 100644
--- a/src/include/utils/pg_locale.h
+++ b/src/include/utils/pg_locale.h
@@ -24,6 +24,20 @@
 /* use for libc locale names */
 #define LOCALE_NAME_BUFLEN 128
 
+/*
+ * Maximum number of bytes needed to map a single codepoint. Useful for
+ * mapping and processing a single input codepoint at a time with a
+ * statically-allocated buffer.
+ *
+ * With full case mapping, an input codepoint may be mapped to as many as
+ * three output codepoints. See Unicode 16.0.0, section 5.18.2, "Change in
+ * Length":
+ *
+ * https://www.unicode.org/versions/Unicode16.0.0/core-spec/chapter-5/#G29675
+ */
+#define UNICODE_CASEMAP_LEN		3
+#define UNICODE_CASEMAP_BUFSZ	(UNICODE_CASEMAP_LEN * MAX_MULTIBYTE_CHAR_LEN)
+
 /* GUC settings */
 extern PGDLLIMPORT char *locale_messages;
 extern PGDLLIMPORT char *locale_monetary;