longpoll: auto disable gbt when not supported

ccminer.cpp

@@ -740,11 +740,18 @@ static bool get_blocktemplate(CURL *curl, struct work *work)
 	if (!allow_gbt)
 		return false;
 
+	int curl_err = 0;
 	json_t *val = json_rpc_call(curl, rpc_url, rpc_userpass, gbt_req,
-			    want_longpoll, false, NULL);
+			    want_longpoll, have_longpoll, &curl_err);
 
-	if (!val)
+	if (!val && curl_err == -1) {
+		// when getblocktemplate is not supported, disable it
+		allow_gbt = false;
+		if (!opt_quiet) {
+				applog(LOG_BLUE, "gbt not supported, block height notices disabled");
+		}
 		return false;
+	}
 
 	bool rc = gbt_work_decode(json_object_get(val, "result"), work);
 

util.cpp

@@ -526,11 +526,22 @@ json_t *json_rpc_call(CURL *curl, const char *url,
 
 		if (err_val) {
 			json_t *msg = json_object_get(err_val, "message");
-			s = json_dumps(err_val, JSON_INDENT(3));
+			json_t *err_code = json_object_get(err_val, "code");
+			if (curl_err && json_integer_value(err_code))
+				*curl_err = (int) json_integer_value(err_code);
+			json_decref(err_code);
+
+			s = json_dumps(err_val, 0);
 			if (json_is_string(msg)) {
 				free(s);
 				s = strdup(json_string_value(msg));
+				if (have_longpoll && s && !strcmp(s, "method not getwork")) {
+					json_decref(err_val);
+					free(s);
+					goto err_out;
+				}
 			}
+			json_decref(err_val);
 		}
 		else
 			s = strdup("(unknown reason)");