From 98e675ed7af95cb65a594ce730d42390e0118dcb Mon Sep 17 00:00:00 2001 From: Daniel Gustafsson Date: Tue, 5 Dec 2023 14:30:56 +0100 Subject: [PATCH] Fix incorrect error message for IDENTIFY_SYSTEM Commit 5a991ef8692e accidentally reversed the order of the tuples and fields parameters, making the error message incorrectly refer to 3 tuples with 1 field when IDENTIFY_SYSTEM returns 1 tuple and 3 or 4 fields. Fix by changing the order of the parameters. This also adds a comment describing why we check for < 3 when postgres since 9.4 has been sending 4 fields. Backpatch all the way since the bug is almost a decade old. Author: Tomonari Katsumata Reviewed-by: Tom Lane Bug: #18224 Backpatch-through: v12 --- src/backend/replication/libpqwalreceiver/libpqwalreceiver.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c b/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c index 60d5c1fc40..5a1633cc4c 100644 --- a/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c +++ b/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c @@ -381,6 +381,10 @@ libpqrcv_identify_system(WalReceiverConn *conn, TimeLineID *primary_tli) "the primary server: %s", pchomp(PQerrorMessage(conn->streamConn))))); } + /* + * IDENTIFY_SERVER returns 3 columns in 9.3 and earlier, and 4 columns in + * 9.4 and onwards. + */ if (PQnfields(res) < 3 || PQntuples(res) != 1) { int ntuples = PQntuples(res); @@ -391,7 +395,7 @@ libpqrcv_identify_system(WalReceiverConn *conn, TimeLineID *primary_tli) (errcode(ERRCODE_PROTOCOL_VIOLATION), errmsg("invalid response from primary server"), errdetail("Could not identify system: got %d rows and %d fields, expected %d rows and %d or more fields.", - ntuples, nfields, 3, 1))); + ntuples, nfields, 1, 3))); } primary_sysid = pstrdup(PQgetvalue(res, 0, 0)); *primary_tli = pg_strtoint32(PQgetvalue(res, 0, 1));