Don't copy datlocale from template unless provider matches.

jeff-davis · jeff-davis · commit 295a39770e6f · 2025-08-05T09:25:23.000-07:00
During CREATE DATABASE, if changing the locale provider, require that a new locale is specified rather than trying to reinterpret the template's locale using the new provider. This only affects the behavior when the template uses the builtin provider and CREATE DATABASE specifies the ICU provider without specifying the locale. Previously, that may have succeeded due to loose validation by ICU, whereas now that will cause an error. Because it can cause an error, backport only to unreleased versions. Discussion: https://postgr.es/m/5038b33a6dc639009f4b3d43fa6ae0c5ba9e04f7.camel@j-davis.com Backpatch-through: 18
diff --git a/src/backend/commands/dbcommands.c b/src/backend/commands/dbcommands.c
@@ -1052,7 +1052,7 @@ createdb(ParseState *pstate, const CreatedbStmt *stmt)
 		dbctype = src_ctype;
 	if (dblocprovider == '\0')
 		dblocprovider = src_locprovider;
-	if (dblocale == NULL)
+	if (dblocale == NULL && dblocprovider == src_locprovider)
 		dblocale = src_locale;
 	if (dbicurules == NULL)
 		dbicurules = src_icurules;
