Fix first run config validation and reload

Hasty refactoring lead to a broken first run experience due to config validation
being blocked on first run. Unblock that, and also fix a couple other issues:

* When validating path mappings, keep the default if there aren't any user-
  provided mappings, so we don't write empty mappings to the config file.
* Soft-reloading the server after initial setup was broken because the action
  wasn't allowed in RunningWithoutConfig mode.
* The server would be in a broken state if the user's initial setup didn't
  require a server reload (e.g. only changed the log level).

Client/Script/ServerSettingsDialog/PathMappingsTable.js

@@ -196,7 +196,7 @@ export class PathMappingsTable {
         }
 
         return {
-            value : newMappings,
+            value : newMappings.length === 0 ? null : newMappings,
             defaultValue : [],
             isInvalid : false,
         };

Server/Commands/ConfigCommands.js

@@ -1,6 +1,7 @@
 import { ServerConfigState } from '../../Shared/ServerConfig.js';
 
 import { ServerEvents, waitForServerEvent } from '../ServerEvents.js';
+import { ServerState, SetServerState } from '../ServerState.js';
 import { Config } from '../MarkerEditorConfig.js';
 import { PostCommands } from '../../Shared/PostCommands.js';
 import { registerCommand } from './PostCommand.js';
@@ -47,6 +48,7 @@ async function validateConfigValue(setting, value) {
  * @param {SerializedConfig} config
  * @param {ServerResponse} response */
 async function setConfig(config, response) {
+    const oldConfigState = Config.getValid();
     const newConfig = await Config.trySetConfig(config);
     switch (newConfig.config.state) {
         case ServerConfigState.FullReloadNeeded:
@@ -56,7 +58,15 @@ async function setConfig(config, response) {
             await waitForServerEvent(ServerEvents.SoftRestart, response, newConfig);
             break;
         default:
-            sendJsonSuccess(response, newConfig);
+            // If we were previously in a valid state, we can just mark the server as
+            // running and return. Otherwise, we need to do a reload, since an invalid
+            // state implies we haven't set up any of our core classes.
+            if (oldConfigState === ServerConfigState.Valid) {
+                SetServerState(ServerState.Running);
+                sendJsonSuccess(response, newConfig);
+            } else {
+                await waitForServerEvent(ServerEvents.SoftRestart, response, newConfig);
+            }
             break;
     }
 }

Server/MarkerEditor.js

@@ -307,7 +307,7 @@ function userResume(res) {
  * @param {ServerResponse} res */
 async function userReload(res, data) {
     Log.verbose('Attempting to reload marker data');
-    if (GetServerState() !== ServerState.Running) {
+    if (![ServerState.Running, ServerState.RunningWithoutConfig].includes(GetServerState())) {
         return sendJsonError(res, new ServerError('Server must be running in order to reload.', 400));
     }
 

Server/PostCommands.js

@@ -16,7 +16,7 @@ import ServerError from './ServerError.js';
 const Log = new ContextualLog('POSTCommands');
 
 /** Subset of server commands that we accept when the config files doesn't exist or is in a bad state. */
-const badStateWhitelist = new Set(['get_config', 'valid_config', 'valid_cfg_v', 'set_config']);
+const badStateWhitelist = new Set(['get_config', 'validate_config', 'valid_cfg_v', 'set_config']);
 
 /**
  * Verify that the given endpoint is allowed given the current server state.