lightningd: make plugin_kill() free the plugin.

This is what I expected from plugin_kill, and now all the callers do the
equivalent anywat, it's easy.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

lightningd/plugin.c

@@ -216,6 +216,7 @@ void plugin_kill(struct plugin *plugin, char *fmt, ...)
 	}
 
 	check_plugins_resolved(plugin->plugins);
+	tal_free(plugin);
 }
 
 /**
@@ -483,7 +484,8 @@ static struct io_plan *plugin_read_json(struct io_conn *conn,
 
 		if (err) {
 			plugin_kill(plugin, "%s", err);
-			return io_close(plugin->stdout_conn);
+			/* plugin_kill frees plugin */
+			return io_close(NULL);
 		}
 	} while (success);
 
@@ -966,11 +968,12 @@ static const char *plugin_hooks_add(struct plugin *plugin, const char *buffer,
 
 static void plugin_manifest_timeout(struct plugin *plugin)
 {
+	bool startup = plugin->plugins->startup;
 	plugin_kill(plugin,
 		    "failed to respond to \"%s\" in time, terminating.",
 		    plugin->plugin_state == AWAITING_GETMANIFEST_RESPONSE
 		    ? "getmanifest" : "init");
-	if (plugin->plugins->startup)
+	if (startup)
 		fatal("Can't recover from plugin failure, terminating.");
 }
 
@@ -1286,7 +1289,6 @@ bool plugins_send_getmanifest(struct plugins *plugins)
 			fatal("error starting plugin '%s': %s", p->cmd,
 			      strerror(errno));
 		plugin_kill(p, "error starting: %s", strerror(errno));
-		tal_free(p);
 	}
 
 	return sent;

lightningd/plugin_control.c

@@ -97,12 +97,6 @@ plugin_dynamic_startdir(struct command *cmd, const char *dir_path)
 	return command_still_pending(cmd);
 }
 
-static void clear_plugin(struct plugin *p, const char *name)
-{
-	plugin_kill(p, "%s stopped by lightningd via RPC", name);
-	tal_free(p);
-}
-
 static struct command_result *
 plugin_dynamic_stop(struct command *cmd, const char *plugin_name)
 {
@@ -116,7 +110,7 @@ plugin_dynamic_stop(struct command *cmd, const char *plugin_name)
 				                    "%s cannot be managed when "
 				                    "lightningd is up",
 				                    plugin_name);
-			clear_plugin(p, plugin_name);
+			plugin_kill(p, "stopped by lightningd via RPC");
 			response = json_stream_success(cmd);
 			if (deprecated_apis)
 				json_add_string(response, "",

tests/test_plugin.py

@@ -229,7 +229,7 @@ def test_plugin_command(node_factory):
     # Make sure the plugin behaves normally after stop and restart
     assert("Successfully stopped helloworld.py."
            == n.rpc.plugin_stop(plugin="helloworld.py")["result"])
-    n.daemon.wait_for_log(r"Killing plugin: helloworld.py")
+    n.daemon.wait_for_log(r"Killing plugin: stopped by lightningd via RPC")
     n.rpc.plugin_start(plugin=os.path.join(os.getcwd(), "contrib/plugins/helloworld.py"))
     n.daemon.wait_for_log(r"Plugin helloworld.py initialized")
     assert("Hello world" == n.rpc.call(method="hello"))
@@ -237,7 +237,7 @@ def test_plugin_command(node_factory):
     # Now stop the helloworld plugin
     assert("Successfully stopped helloworld.py."
            == n.rpc.plugin_stop(plugin="helloworld.py")["result"])
-    n.daemon.wait_for_log(r"Killing plugin: helloworld.py")
+    n.daemon.wait_for_log(r"Killing plugin: stopped by lightningd via RPC")
     # Make sure that the 'hello' command from the helloworld.py plugin
     # is not available anymore.
     cmd = [hlp for hlp in n.rpc.help()["help"] if "hello" in hlp["command"]]