libpq_pline_add_some_tests.diff

diff --git a/src/test/modules/libpq_pipeline/libpq_pipeline.c b/src/test/modules/libpq_pipeline/libpq_pipeline.c
index 0ff563f59a..84734f5d41 100644
--- a/src/test/modules/libpq_pipeline/libpq_pipeline.c
+++ b/src/test/modules/libpq_pipeline/libpq_pipeline.c
@@ -53,6 +53,8 @@ static const char *const insert_sql =
 static const char *const insert_sql2 =
 "INSERT INTO pq_pipeline_demo(itemno,int8filler) VALUES ($1, $2)";
 
+Oid	oid_pg_backend_pid;
+
 /* max char length of an int32/64, plus sign and null terminator */
 #define MAXINTLEN 12
 #define MAXINT8LEN 20
@@ -86,6 +88,24 @@ pg_fatal_impl(int line, const char *fmt,...)
 	exit(1);
 }
 
+/* returns true if PQfn succeeded */
+static bool
+PQfn_succeed(PGconn *conn)
+{
+	PGresult   *res;
+	int			res_buf;
+	int			res_len;
+
+	/* PQfn should fail in pipeline mode */
+	if ((res = PQfn(conn, oid_pg_backend_pid, &res_buf, &res_len, 1, NULL, 0))
+		!= NULL &&
+		PQresultStatus(res) == PGRES_COMMAND_OK)
+		return true;
+
+	return false;
+}
+
+
 static void
 test_disallowed_in_pipeline(PGconn *conn)
 {
@@ -93,6 +113,9 @@ test_disallowed_in_pipeline(PGconn *conn)
 
 	fprintf(stderr, "test error cases... ");
 
+	if (oid_pg_backend_pid == 0)
+		pg_fatal("Failed to obtain functino oid: %s", PQgetvalue(res, 0, 0));
+		
 	if (PQisnonblocking(conn))
 		pg_fatal("Expected blocking connection mode");
 
@@ -107,6 +130,10 @@ test_disallowed_in_pipeline(PGconn *conn)
 	if (PQresultStatus(res) != PGRES_FATAL_ERROR)
 		pg_fatal("PQexec should fail in pipeline mode but succeeded");
 
+	/* PQfn should fail in pipeline mode */
+	if (PQfn_succeed(conn))
+		pg_fatal("PQfn succeeded while in pipeline mode");
+
 	/* Entering pipeline mode when already in pipeline mode is OK */
 	if (PQenterPipelineMode(conn) != 1)
 		pg_fatal("re-entering pipeline mode should be a no-op but failed");
@@ -1014,6 +1041,18 @@ test_simple_pipeline(PGconn *conn)
 	PQclear(res);
 	res = NULL;
 
+	/* PQfn shoud be error no-op while PGASYNC_PIPELINE_IDLE */
+	if (PQfn_succeed(conn))
+		pg_fatal("PQfn succeeded while in pipeline mode");
+
+	/*
+	 * Trial to getting out of pipeline mode while PGASYNC_PIPELINE_IDLE should
+	 * gracefully fail.
+	 */
+	if (PQexitPipelineMode(conn) != 0)
+		pg_fatal("exiting pipeline mode after query but before sync succeeded incorrectly");
+
+	/* This PQgetResult moves async status to PGASYNC_BUSY */
 	if (PQgetResult(conn) != NULL)
 		pg_fatal("PQgetResult returned something extra after first query result.");
 
@@ -1627,6 +1666,15 @@ main(int argc, char **argv)
 	if (PQresultStatus(res) != PGRES_COMMAND_OK)
 		pg_fatal("failed to set force_parallel_mode: %s", PQerrorMessage(conn));
 
+	/* obtain function OID of pg_backend_pid for PQfn test */
+	res = PQexec(conn, "SELECT 'pg_backend_pid'::regproc::int");
+	if (!res ||
+		(PQresultStatus(res) != PGRES_COMMAND_OK &&
+		 PQresultStatus(res) != PGRES_TUPLES_OK))
+		pg_fatal("Failed to obtain functino oid");
+
+	oid_pg_backend_pid = atoi(PQgetvalue(res, 0, 0));
+
 	/* Set the trace file, if requested */
 	if (tracefile != NULL)
 	{