From 3d8899093a0f07e023711c96c4741d6fb40ecba9 Mon Sep 17 00:00:00 2001 From: Amit Langote Date: Fri, 17 Apr 2026 12:26:22 +0900 Subject: [PATCH v4] Reject invalid databases in pg_get_database_ddl() An invalid database has datconnlimit set to -2. pg_get_database_ddl() emits this verbatim as CONNECTION LIMIT = -2, which ALTER DATABASE rejects. Error out early instead. Reported-by: Lakshmi N Author: Lakshmi N Reviewed-by: Amit Langote Reviewed-by: Euler Taveira Reviewed-by: Hu Xunqi Discussion: https://postgr.es/m/CA+3i_M8m1k2gFch+tU0JmAQh9FRV+pFrfTXDrJo+BqmwsTmOhg@mail.gmail.com --- src/backend/utils/adt/ddlutils.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/src/backend/utils/adt/ddlutils.c b/src/backend/utils/adt/ddlutils.c index c4f9f86c43e..d83cda3342e 100644 --- a/src/backend/utils/adt/ddlutils.c +++ b/src/backend/utils/adt/ddlutils.c @@ -887,6 +887,16 @@ pg_get_database_ddl_internal(Oid dbid, bool pretty, dbform = (Form_pg_database) GETSTRUCT(tuple); dbname = pstrdup(NameStr(dbform->datname)); + /* + * Reject invalid databases. Deparsing a pg_database row in invalid state + * can produce SQL that is not executable, such as CONNECTION LIMIT = -2. + */ + if (database_is_invalid_form(dbform)) + ereport(ERROR, + (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE), + errmsg("cannot generate DDL for invalid database \"%s\"", + dbname))); + /* * We don't support generating DDL for system databases. The primary * reason for this is that users shouldn't be recreating them. -- 2.47.3