try to improve link handling

src/linuxrunner.js

@@ -450,6 +450,26 @@ function linuxPathFor(file) {
   return abs
 }
 
+// The document a shortcut was handed. The sandbox cannot hand it over by
+// itself: a file out of the user's home is buried under the prefix home, one
+// out of /tmp sits behind the private tmpfs, and the rest of the machine is
+// read-only. So it is mounted where the app was told it is, writable - the way
+// a Wine app gets it as Z:\... and may save it. Prefix data needs nothing: it
+// already is the app's own writable home.
+function handedFileBinds({ openFile, root }) {
+  if (!openFile) return []
+  let abs = ''
+  try {
+    abs = fs.realpathSync(String(openFile))
+    if (!fs.statSync(abs).isFile()) return []
+  } catch {
+    // a path that is gone must not become a bind bwrap would refuse
+    return []
+  }
+  if (abs === root || abs.startsWith(root + path.sep)) return []
+  return [abs]
+}
+
 function bwrapSource() {
   const devices = ['/dev/shm', '/dev/dri', '/dev/snd', '/dev/input'].filter(d => fs.existsSync(d))
   const x11 = fs.existsSync('/tmp/.X11-unix') ? '/tmp/.X11-unix' : ''
@@ -481,7 +501,7 @@ async function runLinuxGame({ game, sandbox, onExit, openFile, handoff = false }
   if (chosen.backend === 'bwrap') {
     const source = bwrapSource()
     cmd = 'bwrap'
-    args = [...buildBwrapArgs({ dataRoot: root, user: source.user, devices: source.devices, x11: source.x11, runUser: source.runUser, shares: source.shares, appDir: writableAppDir(game), urlOpener: routing }), '--', exe, ...argList]
+    args = [...buildBwrapArgs({ dataRoot: root, user: source.user, devices: source.devices, x11: source.x11, runUser: source.runUser, shares: source.shares, appDir: writableAppDir(game), openFiles: handedFileBinds({ openFile, root }), urlOpener: routing }), '--', exe, ...argList]
     header.push(`[plwl] HOME=${env.HOME}`)
   }
 
@@ -489,12 +509,7 @@ async function runLinuxGame({ game, sandbox, onExit, openFile, handoff = false }
 }
 
 module.exports = {
-  DATA_DIRS,
-  XDG_LAYOUT,
-  SYSTEM_DIRS,
   DESKTOP_SEEDS,
-  DATA_SHARES,
-  X11_ENV,
   SHIM_REL,
   OPENER_REL,
   MIME_REL,
@@ -509,10 +524,10 @@ module.exports = {
   ensureLinuxPfx,
   resetSeededConfig,
   dataShares,
-  syncDesktopConfig,
   buildLinuxEnv,
   pickBackend,
   isolationLine,
   linuxPathFor,
+  handedFileBinds,
   runLinuxGame
 }