v3-0005-Change-wchar2char-and-char2wchar-to-accept-a-loca.patch

From cfc6a2d1dacc51dd7e09291eaa1d4cac350625c7 Mon Sep 17 00:00:00 2001
From: Jeff Davis <jeff@j-davis.com>
Date: Wed, 11 Jun 2025 10:11:16 -0700
Subject: [PATCH v3 5/7] Change wchar2char() and char2wchar() to accept a
 locale_t.

These are libc-specific functions, so accepting a locale_t makes more
sense than accepting a pg_locale_t (which could use another provider).

Also, no longer accept NULL.
---
 src/backend/tsearch/ts_locale.c        |  4 +--
 src/backend/tsearch/wparser_def.c      |  2 +-
 src/backend/utils/adt/pg_locale.c      |  2 +-
 src/backend/utils/adt/pg_locale_libc.c | 42 +++++++++-----------------
 src/include/utils/pg_locale.h          |  4 +--
 5 files changed, 20 insertions(+), 34 deletions(-)

diff --git a/src/backend/tsearch/ts_locale.c b/src/backend/tsearch/ts_locale.c
index b77d8c23d36..4801fe90089 100644
--- a/src/backend/tsearch/ts_locale.c
+++ b/src/backend/tsearch/ts_locale.c
@@ -36,7 +36,7 @@ t_isalpha(const char *ptr)
 {
 	int			clen = pg_mblen(ptr);
 	wchar_t		character[WC_BUF_LEN];
-	pg_locale_t mylocale = 0;	/* TODO */
+	locale_t	mylocale = 0;	/* TODO */
 
 	if (clen == 1 || database_ctype_is_c)
 		return isalpha(TOUCHAR(ptr));
@@ -51,7 +51,7 @@ t_isalnum(const char *ptr)
 {
 	int			clen = pg_mblen(ptr);
 	wchar_t		character[WC_BUF_LEN];
-	pg_locale_t mylocale = 0;	/* TODO */
+	locale_t	mylocale = 0;	/* TODO */
 
 	if (clen == 1 || database_ctype_is_c)
 		return isalnum(TOUCHAR(ptr));
diff --git a/src/backend/tsearch/wparser_def.c b/src/backend/tsearch/wparser_def.c
index 79bcd32a063..e2dd3da3aa3 100644
--- a/src/backend/tsearch/wparser_def.c
+++ b/src/backend/tsearch/wparser_def.c
@@ -299,7 +299,7 @@ TParserInit(char *str, int len)
 	 */
 	if (prs->charmaxlen > 1)
 	{
-		pg_locale_t mylocale = 0;	/* TODO */
+		locale_t	mylocale = 0;	/* TODO */
 
 		prs->usewide = true;
 		if (database_ctype_is_c)
diff --git a/src/backend/utils/adt/pg_locale.c b/src/backend/utils/adt/pg_locale.c
index 97c2ac1faf9..ce50e9e15d0 100644
--- a/src/backend/utils/adt/pg_locale.c
+++ b/src/backend/utils/adt/pg_locale.c
@@ -998,7 +998,7 @@ get_iso_localename(const char *winlocname)
 		char	   *hyphen;
 
 		/* Locale names use only ASCII, any conversion locale suffices. */
-		rc = wchar2char(iso_lc_messages, buffer, sizeof(iso_lc_messages), NULL);
+		rc = wchar2char(iso_lc_messages, buffer, sizeof(iso_lc_messages), LC_C_LOCALE);
 		if (rc == -1 || rc == sizeof(iso_lc_messages))
 			return NULL;
 
diff --git a/src/backend/utils/adt/pg_locale_libc.c b/src/backend/utils/adt/pg_locale_libc.c
index a3d8b51a7d9..998bfa857f0 100644
--- a/src/backend/utils/adt/pg_locale_libc.c
+++ b/src/backend/utils/adt/pg_locale_libc.c
@@ -463,7 +463,7 @@ strlower_libc_mb(char *dest, size_t destsize, const char *src, ssize_t srclen,
 	/* Output workspace cannot have more codes than input bytes */
 	workspace = (wchar_t *) palloc((srclen + 1) * sizeof(wchar_t));
 
-	char2wchar(workspace, srclen + 1, src, srclen, locale);
+	char2wchar(workspace, srclen + 1, src, srclen, loc);
 
 	for (curr_char = 0; workspace[curr_char] != 0; curr_char++)
 		workspace[curr_char] = towlower_l(workspace[curr_char], loc);
@@ -474,7 +474,7 @@ strlower_libc_mb(char *dest, size_t destsize, const char *src, ssize_t srclen,
 	max_size = curr_char * pg_database_encoding_max_length();
 	result = palloc(max_size + 1);
 
-	result_size = wchar2char(result, workspace, max_size + 1, locale);
+	result_size = wchar2char(result, workspace, max_size + 1, loc);
 
 	if (result_size + 1 > destsize)
 		return result_size;
@@ -558,7 +558,7 @@ strtitle_libc_mb(char *dest, size_t destsize, const char *src, ssize_t srclen,
 	/* Output workspace cannot have more codes than input bytes */
 	workspace = (wchar_t *) palloc((srclen + 1) * sizeof(wchar_t));
 
-	char2wchar(workspace, srclen + 1, src, srclen, locale);
+	char2wchar(workspace, srclen + 1, src, srclen, loc);
 
 	for (curr_char = 0; workspace[curr_char] != 0; curr_char++)
 	{
@@ -575,7 +575,7 @@ strtitle_libc_mb(char *dest, size_t destsize, const char *src, ssize_t srclen,
 	max_size = curr_char * pg_database_encoding_max_length();
 	result = palloc(max_size + 1);
 
-	result_size = wchar2char(result, workspace, max_size + 1, locale);
+	result_size = wchar2char(result, workspace, max_size + 1, loc);
 
 	if (result_size + 1 > destsize)
 		return result_size;
@@ -646,7 +646,7 @@ strupper_libc_mb(char *dest, size_t destsize, const char *src, ssize_t srclen,
 	/* Output workspace cannot have more codes than input bytes */
 	workspace = (wchar_t *) palloc((srclen + 1) * sizeof(wchar_t));
 
-	char2wchar(workspace, srclen + 1, src, srclen, locale);
+	char2wchar(workspace, srclen + 1, src, srclen, loc);
 
 	for (curr_char = 0; workspace[curr_char] != 0; curr_char++)
 		workspace[curr_char] = towupper_l(workspace[curr_char], loc);
@@ -657,7 +657,7 @@ strupper_libc_mb(char *dest, size_t destsize, const char *src, ssize_t srclen,
 	max_size = curr_char * pg_database_encoding_max_length();
 	result = palloc(max_size + 1);
 
-	result_size = wchar2char(result, workspace, max_size + 1, locale);
+	result_size = wchar2char(result, workspace, max_size + 1, loc);
 
 	if (result_size + 1 > destsize)
 		return result_size;
@@ -1207,10 +1207,12 @@ wcstombs_l(char *dest, const wchar_t *src, size_t n, locale_t loc)
  * zero-terminated.  The output will be zero-terminated iff there is room.
  */
 size_t
-wchar2char(char *to, const wchar_t *from, size_t tolen, pg_locale_t locale)
+wchar2char(char *to, const wchar_t *from, size_t tolen, locale_t loc)
 {
 	size_t		result;
 
+	Assert(loc != NULL);
+
 	if (tolen == 0)
 		return 0;
 
@@ -1237,16 +1239,7 @@ wchar2char(char *to, const wchar_t *from, size_t tolen, pg_locale_t locale)
 	}
 	else
 #endif							/* WIN32 */
-	if (locale == (pg_locale_t) 0)
-	{
-		/* Use wcstombs directly for the default locale */
-		result = wcstombs(to, from, tolen);
-	}
-	else
-	{
-		/* Use wcstombs_l for nondefault locales */
-		result = wcstombs_l(to, from, tolen, locale->info.lt);
-	}
+		result = wcstombs_l(to, from, tolen, loc);
 
 	return result;
 }
@@ -1262,10 +1255,12 @@ wchar2char(char *to, const wchar_t *from, size_t tolen, pg_locale_t locale)
  */
 size_t
 char2wchar(wchar_t *to, size_t tolen, const char *from, size_t fromlen,
-		   pg_locale_t locale)
+		   locale_t loc)
 {
 	size_t		result;
 
+	Assert(loc != NULL);
+
 	if (tolen == 0)
 		return 0;
 
@@ -1297,16 +1292,7 @@ char2wchar(wchar_t *to, size_t tolen, const char *from, size_t fromlen,
 		/* mbstowcs requires ending '\0' */
 		char	   *str = pnstrdup(from, fromlen);
 
-		if (locale == (pg_locale_t) 0)
-		{
-			/* Use mbstowcs directly for the default locale */
-			result = mbstowcs(to, str, tolen);
-		}
-		else
-		{
-			/* Use mbstowcs_l for nondefault locales */
-			result = mbstowcs_l(to, str, tolen, locale->info.lt);
-		}
+		result = mbstowcs_l(to, str, tolen, loc);
 
 		pfree(str);
 	}
diff --git a/src/include/utils/pg_locale.h b/src/include/utils/pg_locale.h
index 9735d15ceb2..d008b49e3c7 100644
--- a/src/include/utils/pg_locale.h
+++ b/src/include/utils/pg_locale.h
@@ -218,8 +218,8 @@ extern void report_newlocale_failure(const char *localename);
 
 /* These functions convert from/to libc's wchar_t, *not* pg_wchar_t */
 extern size_t wchar2char(char *to, const wchar_t *from, size_t tolen,
-						 pg_locale_t locale);
+						 locale_t loc);
 extern size_t char2wchar(wchar_t *to, size_t tolen,
-						 const char *from, size_t fromlen, pg_locale_t locale);
+						 const char *from, size_t fromlen, locale_t loc);
 
 #endif							/* _PG_LOCALE_ */
-- 
2.43.0