minimal-ws-client: fix couple of breakages

minimal-examples/ws-client/minimal-ws-client-ping/README.md

@@ -18,6 +18,7 @@ Option|Meaning
 --server|Use a specific server instead of libwebsockets.org, eg `--server localhost`.  Implies LCCSCF_ALLOW_SELFSIGNED
 --port|Use a specific port instead of 443, eg `--port 7681`
 -z|Send zero-length pings for testing
+--protocol|Use a specific ws subprotocol rather than lws-mirror-protocol, eg, `--protocol myprotocol`
 
 ## usage
 

minimal-examples/ws-client/minimal-ws-client-ping/minimal-ws-client-ping.c

@@ -19,7 +19,7 @@ static struct lws_context *context;
 static struct lws *client_wsi;
 static int interrupted, zero_length_ping, port = 443,
 	   ssl_connection = LCCSCF_USE_SSL;
-static const char *server_address = "libwebsockets.org", *pro = "lws-ping-test";
+static const char *server_address = "libwebsockets.org", *pro = "lws-mirror-protocol";
 
 struct pss {
 	int send_a_ping;
@@ -40,7 +40,7 @@ connect_client(void)
 	i.origin = i.address;
 	i.ssl_connection = ssl_connection;
 	i.protocol = pro;
-	i.local_protocol_name = pro;
+	i.local_protocol_name = "lws-ping-test";
 	i.pwsi = &client_wsi;
 
 	return !lws_client_connect_via_info(&i);
@@ -185,6 +185,9 @@ int main(int argc, const char **argv)
 	if (lws_cmdline_option(argc, argv, "-z"))
 		zero_length_ping = 1;
 
+	if ((p = lws_cmdline_option(argc, argv, "--protocol")))
+		pro = p;
+
 	if ((p = lws_cmdline_option(argc, argv, "--server"))) {
 		server_address = p;
 		pro = "lws-minimal";

minimal-examples/ws-client/minimal-ws-client-tx/minimal-ws-client.c

@@ -249,7 +249,7 @@ skip:
 		 * We respond by scheduling a writable callback for the
 		 * connected client, if any.
 		 */
-		if (vhd->client_wsi && vhd->established)
+		if (vhd && vhd->client_wsi && vhd->established)
 			lws_callback_on_writable(vhd->client_wsi);
 		break;