backend/launcher: don't try to pass empty string as additional argument if falsy (empty, null, ...)

If the additional command line arguments are unset/set to an empty
string, the sideload command launcher likewise used to pass an empty
argument to the launched application.

While that is usually harmless, some applications try to parse this
argument and (rightfully) complain and usually exit with an error.

Make sure that we only pass additional arguments if they are actually
set, fixing that issue.

This has been encountered with Palia's launcher.

While at it, also fix a log line by including additional arguments and a
typo in a comment.

Author: rdbrschf

src/backend/storeManagers/storeManagerCommon/games.ts

@@ -151,6 +151,8 @@ export async function launchGame(
 
   const gameSettings = await getAppSettings(appName)
   const { launcherArgs } = gameSettings
+  const extraArgs = shlex.split(launcherArgs ?? '')
+  const extraArgsJoined = extraArgs.join(' ')
 
   if (executable) {
     const isNative = gameManagerMap[runner].isNative(appName)
@@ -196,15 +198,15 @@ export async function launchGame(
     // Native
     if (isNative) {
       logInfo(
-        `launching native sideloaded game: ${executable} ${launcherArgs ?? ''}`,
+        `launching native sideloaded game: ${executable} ${extraArgsJoined}`,
         LogPrefix.Backend
       )
 
       try {
         await access(executable, FS_CONSTANTS.X_OK)
       } catch (error) {
         logWarning(
-          'File not executable, changing permissions temporarilly',
+          'File not executable, changing permissions temporarily',
           LogPrefix.Backend
         )
         // On Mac, it gives an error when changing the permissions of the file inside the app bundle. But we need it for other executables like scripts.
@@ -213,15 +215,14 @@ export async function launchGame(
         }
       }
 
-      const commandParts = shlex.split(launcherArgs ?? '')
       const env = {
         ...process.env,
         ...setupWrapperEnvVars({ appName, appRunner: runner }),
         ...setupEnvVars(gameSettings, gameInfo.install.install_path)
       }
 
       await callRunner(
-        commandParts,
+        extraArgs,
         {
           name: runner,
           logPrefix: LogPrefix.Backend,
@@ -245,12 +246,12 @@ export async function launchGame(
     }
 
     logInfo(
-      `launching non-native sideloaded: ${executable}}`,
+      `launching non-native sideloaded: ${executable} ${extraArgsJoined}`,
       LogPrefix.Backend
     )
 
     await runWineCommand({
-      commandParts: [executable, launcherArgs ?? ''],
+      commandParts: [executable, ...extraArgs],
       gameSettings,
       wait: true,
       protonVerb: 'waitforexitandrun',