Fix libpq example programs

When these programs call pg_catalog.set_config, they need to check for
PGRES_TUPLES_OK instead of PGRES_COMMAND_OK.  Fix for
5770172cb0.

Reported-by: Ideriha, Takeshi <ideriha.takeshi@jp.fujitsu.com>

doc/src/sgml/libpq.sgml

@@ -8440,7 +8440,7 @@ main(int argc, char **argv)
     /* Set always-secure search path, so malicous users can't take control. */
     res = PQexec(conn,
                  "SELECT pg_catalog.set_config('search_path', '', false)");
-    if (PQresultStatus(res) != PGRES_COMMAND_OK)
+    if (PQresultStatus(res) != PGRES_TUPLES_OK)
     {
         fprintf(stderr, "SET failed: %s", PQerrorMessage(conn));
         PQclear(res);
@@ -8610,7 +8610,7 @@ main(int argc, char **argv)
     /* Set always-secure search path, so malicous users can't take control. */
     res = PQexec(conn,
                  "SELECT pg_catalog.set_config('search_path', '', false)");
-    if (PQresultStatus(res) != PGRES_COMMAND_OK)
+    if (PQresultStatus(res) != PGRES_TUPLES_OK)
     {
         fprintf(stderr, "SET failed: %s", PQerrorMessage(conn));
         PQclear(res);

doc/src/sgml/lobj.sgml

@@ -936,7 +936,7 @@ main(int argc, char **argv)
     /* Set always-secure search path, so malicous users can't take control. */
     res = PQexec(conn,
                  "SELECT pg_catalog.set_config('search_path', '', false)");
-    if (PQresultStatus(res) != PGRES_COMMAND_OK)
+    if (PQresultStatus(res) != PGRES_TUPLES_OK)
     {
         fprintf(stderr, "SET failed: %s", PQerrorMessage(conn));
         PQclear(res);

src/test/examples/testlibpq.c

@@ -51,7 +51,7 @@ main(int argc, char **argv)
 	/* Set always-secure search path, so malicous users can't take control. */
 	res = PQexec(conn,
 				 "SELECT pg_catalog.set_config('search_path', '', false)");
-	if (PQresultStatus(res) != PGRES_COMMAND_OK)
+	if (PQresultStatus(res) != PGRES_TUPLES_OK)
 	{
 		fprintf(stderr, "SET failed: %s", PQerrorMessage(conn));
 		PQclear(res);

src/test/examples/testlibpq2.c

@@ -80,7 +80,7 @@ main(int argc, char **argv)
 	/* Set always-secure search path, so malicous users can't take control. */
 	res = PQexec(conn,
 				 "SELECT pg_catalog.set_config('search_path', '', false)");
-	if (PQresultStatus(res) != PGRES_COMMAND_OK)
+	if (PQresultStatus(res) != PGRES_TUPLES_OK)
 	{
 		fprintf(stderr, "SET failed: %s", PQerrorMessage(conn));
 		PQclear(res);

src/test/examples/testlibpq4.c

@@ -37,7 +37,7 @@ check_prepare_conn(PGconn *conn, const char *dbName)
 	/* Set always-secure search path, so malicous users can't take control. */
 	res = PQexec(conn,
 				 "SELECT pg_catalog.set_config('search_path', '', false)");
-	if (PQresultStatus(res) != PGRES_COMMAND_OK)
+	if (PQresultStatus(res) != PGRES_TUPLES_OK)
 	{
 		fprintf(stderr, "SET failed: %s", PQerrorMessage(conn));
 		PQclear(res);

src/test/examples/testlo.c

@@ -235,7 +235,7 @@ main(int argc, char **argv)
 	/* Set always-secure search path, so malicous users can't take control. */
 	res = PQexec(conn,
 				 "SELECT pg_catalog.set_config('search_path', '', false)");
-	if (PQresultStatus(res) != PGRES_COMMAND_OK)
+	if (PQresultStatus(res) != PGRES_TUPLES_OK)
 	{
 		fprintf(stderr, "SET failed: %s", PQerrorMessage(conn));
 		PQclear(res);

src/test/examples/testlo64.c

@@ -259,7 +259,7 @@ main(int argc, char **argv)
 	/* Set always-secure search path, so malicous users can't take control. */
 	res = PQexec(conn,
 				 "SELECT pg_catalog.set_config('search_path', '', false)");
-	if (PQresultStatus(res) != PGRES_COMMAND_OK)
+	if (PQresultStatus(res) != PGRES_TUPLES_OK)
 	{
 		fprintf(stderr, "SET failed: %s", PQerrorMessage(conn));
 		PQclear(res);