fix launching shortcuts

src/main.js

@@ -1,7 +1,7 @@
 'use strict'
 
 const { app } = require('electron')
-const { ensureDirs } = require('./paths')
+const { ensureDirs, DIRS } = require('./paths')
 const i18n = require('./i18n')
 const wines = require('./wines')
 const { registerIpc } = require('./ipc')
@@ -27,13 +27,29 @@ let autoQuitWhenDone = false // headless boot: quit after that game exits
 const getWindow = () => win
 
 // --- single instance ---------------------------------------------------------
+// Diagnostics: the shortcut handoff path is invisible otherwise (a failing
+// handoff just "does nothing" for the user). Everything lands in a small
+// trace file next to the launcher data so problems are reproducible.
+function trace(msg) {
+  try {
+    const file = path.join(DIRS.DATA, 'instance-trace.log')
+    // keep the trace tiny: drop it once it grows past ~64 KiB
+    try {
+      if (fs.existsSync(file) && fs.statSync(file).size > 64 * 1024) fs.rmSync(file, { force: true })
+    } catch {}
+    fs.appendFileSync(file, `${new Date().toISOString()} ${msg}\n`)
+  } catch {}
+}
+
 // A second launcher invocation (e.g. a desktop shortcut with --launch <id>)
 // hands its arguments to the running instance and exits immediately.
 const gotLock = app.requestSingleInstanceLock()
+trace(`boot argv=${process.argv.slice(1).join(' ')} gotLock=${gotLock}`)
 if (!gotLock) {
   app.quit()
 } else {
   app.on('second-instance', (e, argv) => {
+    trace(`second-instance argv=${argv.join(' ')}`)
     const id = parseLaunchId(argv)
     lastHandoffAt = Date.now()
     if (id) launchGame(id)
@@ -49,7 +65,16 @@ let lastHandoffAt = 0
 function parseLaunchId(argv) {
   const args = Array.isArray(argv) ? argv : process.argv
   const i = args.indexOf('--launch')
-  if (i !== -1 && args[i + 1]) return args[i + 1]
+  if (i !== -1) {
+    // Chromium injects its own flags into the second instance's argv and they
+    // can land BETWEEN --launch and the value (e.g. `--launch
+    // --allow-file-access-from-files 1790414564627`), so skip anything that
+    // looks like a flag and take the first non-flag token.
+    for (let j = i + 1; j < args.length; j++) {
+      if (!args[j].startsWith('--')) return args[j]
+    }
+    return null
+  }
   const eq = args.find(a => a.startsWith('--launch='))
   return eq ? eq.slice('--launch='.length) : null
 }
@@ -169,8 +194,10 @@ function wireWindow(w) {
 let gamesService = null
 
 async function launchGame(id) {
+  trace(`launchGame ${id} serviceReady=${!!gamesService}`)
   if (!gamesService) return
   const res = await gamesService.start(getWindow(), id)
+  trace(`launchGame ${id} result=${JSON.stringify(res).slice(0, 200)}`)
   if (res.ok) {
     rebuildTrayMenu()
     // headless boot: when the auto-started game finishes and nothing else is