[CF 5626] v4 - ReplicationSlotRelease() crashes when the instance is in the single user mode

This branch was automatically generated by a robot using patches from an
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https://commitfest.postgresql.org/patch/5626

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on the master branch.

Patch(es): https://www.postgresql.org/message-id/OSCPR01MB149669CFD736D48C4450337DDF5CD2@OSCPR01MB14966.jpnprd01.prod.outlook.com
Author(s): Hayato Kuroda

Author: Commitfest Bot

src/backend/replication/logical/logicalfuncs.c

@@ -113,6 +113,8 @@ pg_logical_slot_get_changes_guts(FunctionCallInfo fcinfo, bool confirm, bool bin
 	List	   *options = NIL;
 	DecodingOutputState *p;
 
+	CheckSlotIsInSingleUserMode();
+
 	CheckSlotPermissions();
 
 	CheckLogicalDecodingRequirements();

src/backend/replication/slot.c

@@ -1442,6 +1442,18 @@ CheckSlotPermissions(void)
 						   "REPLICATION")));
 }
 
+/*
+ * Check whether the instance is in single-user mode.
+ */
+void
+CheckSlotIsInSingleUserMode(void)
+{
+	if (!IsUnderPostmaster)
+		ereport(ERROR,
+				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+				 errmsg("replication slots cannot be used in single-user mode")));
+}
+
 /*
  * Reserve WAL for the currently active slot.
  *

src/backend/replication/slotfuncs.c

@@ -17,6 +17,7 @@
 #include "access/xlogrecovery.h"
 #include "access/xlogutils.h"
 #include "funcapi.h"
+#include "miscadmin.h"
 #include "replication/logical.h"
 #include "replication/slot.h"
 #include "replication/slotsync.h"
@@ -76,6 +77,8 @@ pg_create_physical_replication_slot(PG_FUNCTION_ARGS)
 	if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE)
 		elog(ERROR, "return type must be a row type");
 
+	CheckSlotIsInSingleUserMode();
+
 	CheckSlotPermissions();
 
 	CheckSlotRequirements();
@@ -182,6 +185,8 @@ pg_create_logical_replication_slot(PG_FUNCTION_ARGS)
 	if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE)
 		elog(ERROR, "return type must be a row type");
 
+	CheckSlotIsInSingleUserMode();
+
 	CheckSlotPermissions();
 
 	CheckLogicalDecodingRequirements();
@@ -521,6 +526,8 @@ pg_replication_slot_advance(PG_FUNCTION_ARGS)
 
 	Assert(!MyReplicationSlot);
 
+	CheckSlotIsInSingleUserMode();
+
 	CheckSlotPermissions();
 
 	if (XLogRecPtrIsInvalid(moveto))
@@ -618,9 +625,12 @@ copy_replication_slot(FunctionCallInfo fcinfo, bool logical_slot)
 	TupleDesc	tupdesc;
 	HeapTuple	tuple;
 
+
 	if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE)
 		elog(ERROR, "return type must be a row type");
 
+	CheckSlotIsInSingleUserMode();
+
 	CheckSlotPermissions();
 
 	if (logical_slot)
@@ -898,6 +908,8 @@ pg_sync_replication_slots(PG_FUNCTION_ARGS)
 	char	   *err;
 	StringInfoData app_name;
 
+	CheckSlotIsInSingleUserMode();
+
 	CheckSlotPermissions();
 
 	if (!RecoveryInProgress())

src/include/replication/slot.h

@@ -306,6 +306,7 @@ extern void CheckPointReplicationSlots(bool is_shutdown);
 
 extern void CheckSlotRequirements(void);
 extern void CheckSlotPermissions(void);
+extern void CheckSlotIsInSingleUserMode(void);
 extern ReplicationSlotInvalidationCause
 			GetSlotInvalidationCause(const char *cause_name);
 extern const char *GetSlotInvalidationCauseName(ReplicationSlotInvalidationCause cause);