From 3ebea75f9afab4f526934100b4ba747e9d95bba8 Mon Sep 17 00:00:00 2001 From: Jeff Davis Date: Tue, 4 Nov 2025 16:27:31 -0800 Subject: [PATCH] Special case C_COLLATION_OID in pg_newlocale_from_collation(). Allow pg_newlocale_from_collation(C_COLLATION_OID) to work even if there's no catalog access, which some extensions expect. Not known to be a bug without extensions involved, but backport to 18. Also corrects an issue in master with dummy_c_locale (introduced in commit 5a38104b36) where deterministic was not set. That wasn't a bug, but could have been if that structure was used more widely. Reported-by: Alexander Kukushkin Reviewed-by: Alexander Kukushkin Discussion: https://postgr.es/m/CAFh8B=nj966ECv5vi_u3RYij12v0j-7NPZCXLYzNwOQp9AcPWQ@mail.gmail.com Backpatch-through: 18 --- src/backend/utils/adt/pg_locale.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/src/backend/utils/adt/pg_locale.c b/src/backend/utils/adt/pg_locale.c index f5e31c433a0..fc5b842de29 100644 --- a/src/backend/utils/adt/pg_locale.c +++ b/src/backend/utils/adt/pg_locale.c @@ -134,6 +134,13 @@ static pg_locale_t default_locale = NULL; static bool CurrentLocaleConvValid = false; static bool CurrentLCTimeValid = false; +static struct pg_locale_struct c_locale = { + .provider = COLLPROVIDER_LIBC, + .deterministic = true, + .collate_is_c = true, + .ctype_is_c = true, +}; + /* Cache for collation-related knowledge */ typedef struct @@ -1194,6 +1201,13 @@ pg_newlocale_from_collation(Oid collid) if (collid == DEFAULT_COLLATION_OID) return default_locale; + /* + * Some callers expect C_COLLATION_OID to succeed even without catalog + * access. + */ + if (collid == C_COLLATION_OID) + return &c_locale; + if (!OidIsValid(collid)) elog(ERROR, "cache lookup failed for collation %u", collid); -- 2.47.3