libplugin: fix 'dynamic' field in getmanifest

As a separated commit because it was pre-existent (changelog + xfail test).

This also fix a logical problem in lightningd/plugin_control: we were
assuming a plugin started with 'plugin start' but which did not comport
a 'dynamic' entry in its manifest to be dynamic, though it should have
been treated as static.

Changelog-fixed: plugins: Dynamic C plugins can now be managed when lightningd is up

lightningd/plugin.c

@@ -73,6 +73,7 @@ struct plugin *plugin_register(struct plugins *plugins, const char* path TAKES)
 	p->js_arr = tal_arr(p, struct json_stream *, 0);
 	p->used = 0;
 	p->subscriptions = NULL;
+	p->dynamic = false;
 
 	p->log = new_log(p, plugins->log_book, NULL, "plugin-%s",
 			 path_basename(tmpctx, p->cmd));
@@ -810,22 +811,22 @@ static void plugin_manifest_timeout(struct plugin *plugin)
 	fatal("Can't recover from plugin failure, terminating.");
 }
 
-
 bool plugin_parse_getmanifest_response(const char *buffer,
                                        const jsmntok_t *toks,
                                        const jsmntok_t *idtok,
                                        struct plugin *plugin)
 {
 	const jsmntok_t *resulttok, *dynamictok;
-	bool dynamic_plugin;
 
 	resulttok = json_get_member(buffer, toks, "result");
 	if (!resulttok || resulttok->type != JSMN_OBJECT)
 		return false;
 
 	dynamictok = json_get_member(buffer, resulttok, "dynamic");
-	if (dynamictok && json_to_bool(buffer, dynamictok, &dynamic_plugin))
+	if (dynamictok && !json_to_bool(buffer, dynamictok, &plugin->dynamic))
-		plugin->dynamic = dynamic_plugin;
+		plugin_kill(plugin, "Bad 'dynamic' field ('%.*s')",
+			    json_tok_full_len(dynamictok),
+			    json_tok_full(buffer, dynamictok));
 
 	if (!plugin_opts_add(plugin, buffer, resulttok) ||
 	    !plugin_rpcmethods_add(plugin, buffer, resulttok) ||

lightningd/plugin_control.c

@@ -115,7 +115,7 @@ static struct command_result *plugin_start(struct dynamic_plugin *dp)
 	struct jsonrpc_request *req;
 	struct plugin *p = dp->plugin;
 
-	p->dynamic = true;
+	p->dynamic = false;
 	p_cmd = tal_arrz(NULL, char *, 2);
 	p_cmd[0] = p->cmd;
 	/* In case the plugin create files, this is a better default. */

plugins/libplugin.c

@@ -591,8 +591,7 @@ handle_getmanifest(struct command *getmanifest_cmd)
 		json_add_string(params, NULL, p->hook_subs[i].name);
 	json_array_end(params);
 
-	json_add_string(params, "dynamic",
+	json_add_bool(params, "dynamic", p->restartability == PLUGIN_RESTARTABLE);
-			p->restartability == PLUGIN_RESTARTABLE ? "true" : "false");
 
 	return command_finished(getmanifest_cmd, params);
 }

tests/test_plugin.py

@@ -791,7 +791,6 @@ def test_rpc_command_hook(node_factory):
     l1.rpc.plugin_stop('rpc_command.py')
 
 
-@pytest.mark.xfail(strict=True)
 def test_libplugin(node_factory):
     """Sanity checks for plugins made with libplugin"""
     plugin = os.path.join(os.getcwd(), "tests/plugins/test_libplugin")