v9-0002-Add-define-for-UNICODE_CASEMAP_BUFSZ.patch

From 5538939cae6210a4ee702253b0287e44993b98b4 Mon Sep 17 00:00:00 2001
From: Jeff Davis <jeff@j-davis.com>
Date: Wed, 19 Nov 2025 10:11:52 -0800
Subject: [PATCH v9 02/11] Add #define for UNICODE_CASEMAP_BUFSZ.

Useful for mapping a single codepoint at a time into a
statically-allocated buffer.
---
 src/include/utils/pg_locale.h | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/src/include/utils/pg_locale.h b/src/include/utils/pg_locale.h
index 683e1a0eef8..49fd22bf8eb 100644
--- a/src/include/utils/pg_locale.h
+++ b/src/include/utils/pg_locale.h
@@ -26,6 +26,17 @@
 /* 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 5.18.2, "Change in Length".
+ */
+#define UNICODE_CASEMAP_LEN		3
+#define UNICODE_CASEMAP_BUFSZ	(UNICODE_CASEMAP_LEN * sizeof(char32_t))
+
 /* GUC settings */
 extern PGDLLIMPORT char *locale_messages;
 extern PGDLLIMPORT char *locale_monetary;
-- 
2.43.0