fix dll overrides & add disable UMU

src/prefixes.js

@@ -15,6 +15,7 @@ function seed() {
   if (!defs || !Array.isArray(defs.prefixes) || !defs.prefixes.length) {
     const seeded = { default: MAIN, prefixes: [{ name: MAIN, created: Date.now(), locked: true }] }
     if (!fs.existsSync(prefixPath(MAIN))) fs.mkdirSync(prefixPath(MAIN), { recursive: true })
+    ensureUnifiedPrefix(MAIN)
     writeJson(REGISTRY, seeded)
   }
 }
@@ -42,22 +43,65 @@ function prefixExists(name) {
 }
 
 // Every Windows C: drive a prefix has: plain wine keeps one at the top
-// (WINEPREFIX=<prefix>), Proton-managed prefixes nest one under pfx/
-// (WINEPREFIX=<prefix>/pfx). A prefix used with BOTH wine kinds has both,
-// and an import may come from either one - so callers that can accept
-// several get them all, top level first.
+// (WINEPREFIX=<prefix>), legacy Proton-managed prefixes nest one under pfx/
+// (WINEPREFIX=<prefix>/pfx). A prefix used with BOTH wine kinds has both, and
+// an import may come from either one - so callers that can accept several get
+// them all, top level first. A unified prefix (pfx -> .) reaches the same
+// drive twice; it is reported once.
 function prefixDriveRoots(name) {
   const root = prefixPath(name)
   const found = []
+  const seen = new Set()
   for (const base of [root, path.join(root, 'pfx')]) {
     try {
       const driveC = path.join(base, 'drive_c')
-      if (fs.statSync(driveC).isDirectory()) found.push(driveC)
+      if (!fs.statSync(driveC).isDirectory()) continue
+      const real = fs.realpathSync(driveC)
+      if (seen.has(real)) continue
+      seen.add(real)
+      found.push(driveC)
     } catch {}
   }
   return found
 }
 
+function lstatOrNull(p) {
+  try {
+    return fs.lstatSync(p)
+  } catch {
+    return null
+  }
+}
+
+// Wine keeps its C: drive at <prefix>/drive_c, Proton always runs its prefix
+// from <compatdata>/pfx - and PLWL points compatdata at the launcher's prefix
+// folder, so without a link a prefix used with both wine kinds grows TWO C:
+// drives with separate registries, saves and installed DLLs. Making `pfx` a
+// relative symlink back to the prefix itself collapses them: Proton's
+// <compatdata>/pfx resolves to the prefix root, the exact folder wine uses.
+// Every walker PLWL owns (fsutil, symlinks, LAN sync) treats symlinks as
+// links and never follows them, so the self-reference is safe.
+//
+// Only a prefix that has no pfx AT ALL gets the link - that covers a fresh
+// prefix and a plain-wine prefix first used through Proton. An existing
+// layout is left exactly as it is: a prefix from an older PLWL keeps its real
+// pfx/ folder (and here the two wine kinds keep two C: drives), and a prefix
+// with both real drive_c trees keeps them - moving Windows installs around
+// behind the user's back loses data and breaks the absolute/relative links
+// inside them.
+function ensureUnifiedPrefix(name) {
+  if (!name) return false
+  const pfx = path.join(prefixPath(name), 'pfx')
+  if (lstatOrNull(pfx)) return false
+  try {
+    fs.symlinkSync('.', pfx, 'dir')
+    return true
+  } catch {
+    // the prefix folder may not exist yet - the link is added on creation
+    return false
+  }
+}
+
 // True when a path IS one of a prefix's own roots: the prefix folder, its
 // pfx/ or either drive_c. A copy/move import of such a folder would move the
 // prefix's C: drive (or the whole prefix) into files/apps, gutting it - the
@@ -82,6 +126,7 @@ function createPrefix(name) {
   if (clean.toLowerCase() === MAIN.toLowerCase()) return { ok: false, error: 'alreadyExists' }
   if (fs.existsSync(prefixPath(clean))) return { ok: false, error: 'alreadyExists' }
   fs.mkdirSync(prefixPath(clean), { recursive: true })
+  ensureUnifiedPrefix(clean)
   const defs = listPrefixes()
   defs.prefixes.push({ name: clean, created: Date.now() })
   if (!defs.prefixes.some(p => p.name === defs.default)) defs.default = clean
@@ -153,4 +198,4 @@ function setDefaultPrefix(name) {
   return { ok: true }
 }
 
-module.exports = { listPrefixes, savePrefixes, createPrefix, deletePrefix, renamePrefix, setDefaultPrefix, prefixPath, prefixExists, prefixDriveRoots, isPrefixRoot, healPrefix, MAIN }
+module.exports = { listPrefixes, savePrefixes, createPrefix, deletePrefix, renamePrefix, setDefaultPrefix, prefixPath, prefixExists, prefixDriveRoots, isPrefixRoot, healPrefix, ensureUnifiedPrefix, MAIN }