diff --git a/src/interfaces/libpq/fe-exec.c b/src/interfaces/libpq/fe-exec.c
index 78cff4475cc..919cf5741d4 100644
--- a/src/interfaces/libpq/fe-exec.c
+++ b/src/interfaces/libpq/fe-exec.c
@@ -1196,6 +1196,7 @@ pqSaveParameterStatus(PGconn *conn, const char *name, const char *value)
  *	  Returns 1 if OK, 0 if error occurred.
  *
  * On error, *errmsgp can be set to an error string to be returned.
+ * (Such a string should already be translated via libpq_gettext().)
  * If it is left NULL, the error is presumed to be "out of memory".
  *
  * In single-row mode, we create a new result holding just the current row,
@@ -1986,7 +1987,7 @@ PQsetSingleRowMode(PGconn *conn)
 		(conn->cmd_queue_head->queryclass != PGQUERY_SIMPLE &&
 		 conn->cmd_queue_head->queryclass != PGQUERY_EXTENDED))
 		return 0;
-	if (conn->result || conn->error_result)
+	if (pgHavePendingResult(conn))
 		return 0;
 
 	/* OK, set flag */
@@ -2941,7 +2942,7 @@ PQfn(PGconn *conn,
 	}
 
 	if (conn->sock == PGINVALID_SOCKET || conn->asyncStatus != PGASYNC_IDLE ||
-		conn->result || conn->error_result)
+		pgHavePendingResult(conn))
 	{
 		appendPQExpBufferStr(&conn->errorMessage,
 							 libpq_gettext("connection in wrong state\n"));
diff --git a/src/interfaces/libpq/fe-protocol3.c b/src/interfaces/libpq/fe-protocol3.c
index 94b4a448b90..10c76daf6ed 100644
--- a/src/interfaces/libpq/fe-protocol3.c
+++ b/src/interfaces/libpq/fe-protocol3.c
@@ -209,7 +209,7 @@ pqParseInput3(PGconn *conn)
 				case 'C':		/* command complete */
 					if (pqGets(&conn->workBuffer, conn))
 						return;
-					if (conn->result == NULL)
+					if (!pgHavePendingResult(conn))
 					{
 						conn->result = PQmakeEmptyPGresult(conn,
 														   PGRES_COMMAND_OK);
@@ -263,7 +263,7 @@ pqParseInput3(PGconn *conn)
 					}
 					break;
 				case 'I':		/* empty query */
-					if (conn->result == NULL)
+					if (!pgHavePendingResult(conn))
 					{
 						conn->result = PQmakeEmptyPGresult(conn,
 														   PGRES_EMPTY_QUERY);
@@ -281,7 +281,7 @@ pqParseInput3(PGconn *conn)
 					if (conn->cmd_queue_head &&
 						conn->cmd_queue_head->queryclass == PGQUERY_PREPARE)
 					{
-						if (conn->result == NULL)
+						if (!pgHavePendingResult(conn))
 						{
 							conn->result = PQmakeEmptyPGresult(conn,
 															   PGRES_COMMAND_OK);
@@ -362,7 +362,7 @@ pqParseInput3(PGconn *conn)
 					if (conn->cmd_queue_head &&
 						conn->cmd_queue_head->queryclass == PGQUERY_DESCRIBE)
 					{
-						if (conn->result == NULL)
+						if (!pgHavePendingResult(conn))
 						{
 							conn->result = PQmakeEmptyPGresult(conn,
 															   PGRES_COMMAND_OK);
@@ -2133,7 +2133,7 @@ pqFunctionCall3(PGconn *conn, Oid fnid,
 				 * report COMMAND_OK.  Otherwise, the backend violated the
 				 * protocol, so complain.
 				 */
-				if (!(conn->result || conn->error_result))
+				if (!pgHavePendingResult(conn))
 				{
 					if (status == PGRES_COMMAND_OK)
 					{
diff --git a/src/interfaces/libpq/libpq-int.h b/src/interfaces/libpq/libpq-int.h
index e0cee4b142f..3db6a17db4d 100644
--- a/src/interfaces/libpq/libpq-int.h
+++ b/src/interfaces/libpq/libpq-int.h
@@ -852,6 +852,14 @@ extern void pqTraceOutputNoTypeByteMessage(PGconn *conn, const char *message);
 	(resetPQExpBuffer(&(conn)->errorMessage), \
 	 (conn)->errorReported = 0)
 
+/*
+ * Check whether we have a PGresult pending to be returned --- either a
+ * constructed one in conn->result, or a "virtual" error result that we
+ * don't intend to materialize until the end of the query cycle.
+ */
+#define pgHavePendingResult(conn) \
+	((conn)->result != NULL || (conn)->error_result)
+
 /*
  * this is so that we can check if a connection is non-blocking internally
  * without the overhead of a function call