0001-uncover-logical-change-details-20230703.patch

From e117a1ea78327ebcb85d55fedb3b5e7e3b5c7b27 Mon Sep 17 00:00:00 2001
From: Euler Taveira <euler.taveira@enterprisedb.com>
Date: Mon, 3 Jul 2023 08:54:10 -0300
Subject: [PATCH] uncover logical change details

The commit abc0910e2e0 adds logical change details to error context.
However, the function logicalrep_message_type() introduces an
elog(ERROR) that can hide these details. Instead, avoid elog() and use
??? (that is a synonym for unknown). Spotted by Ashutosh Bapat.

Discussion: https://postgr.es/m/CAExHW5suAEDW-mBZt_qu4RVxWZ1vL54-L%2Bci2zreYWebpzxYsA%40mail.gmail.com
---
 src/backend/replication/logical/proto.c | 11 +++++++----
 src/include/replication/logicalproto.h  |  2 +-
 2 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/src/backend/replication/logical/proto.c b/src/backend/replication/logical/proto.c
index f308713275..fe6ed9f94b 100644
--- a/src/backend/replication/logical/proto.c
+++ b/src/backend/replication/logical/proto.c
@@ -1213,7 +1213,7 @@ logicalrep_read_stream_abort(StringInfo in,
 /*
  * Get string representing LogicalRepMsgType.
  */
-char *
+const char *
 logicalrep_message_type(LogicalRepMsgType action)
 {
 	switch (action)
@@ -1258,7 +1258,10 @@ logicalrep_message_type(LogicalRepMsgType action)
 			return "STREAM PREPARE";
 	}
 
-	elog(ERROR, "invalid logical replication message type \"%c\"", action);
-
-	return NULL;				/* keep compiler quiet */
+	/*
+	 * This function is called to provide context in the error raised when
+	 * applying a logical message. So we can't throw an error here. Return an
+	 * unknown indicator value so that the original error is still reported.
+	 */
+	return "???";
 }
diff --git a/src/include/replication/logicalproto.h b/src/include/replication/logicalproto.h
index 0ea2df5088..c5be981eae 100644
--- a/src/include/replication/logicalproto.h
+++ b/src/include/replication/logicalproto.h
@@ -269,6 +269,6 @@ extern void logicalrep_write_stream_abort(StringInfo out, TransactionId xid,
 extern void logicalrep_read_stream_abort(StringInfo in,
 										 LogicalRepStreamAbortData *abort_data,
 										 bool read_abort_info);
-extern char *logicalrep_message_type(LogicalRepMsgType action);
+extern const char *logicalrep_message_type(LogicalRepMsgType action);
 
 #endif							/* LOGICAL_PROTO_H */
-- 
2.25.1