Fix process tracking for Wine/Proton game processes

findTrackedProcess was only checking /proc/<pid>/comm to match game
executables.  This fails for Wine/Proton because:

1. /proc/comm is truncated to 15 chars (TASK_COMM_LEN), so
   "FalloutNVLauncher.exe" becomes "FalloutNVLaunch" — no match
2. Wine processes show "wine64-preloader" or "start.exe" in comm,
   not the actual game executable name
3. With UMU_ID set, Proton-GE launches via "start.exe /unix <game>"
   adding another indirection layer

Now also checks /proc/<pid>/cmdline which contains the full untruncated
command line including the game .exe path.  Handles both Windows-style
backslash paths (c:\...\game.exe) and Unix paths.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

1 files changed, 61 insertions, 7 deletions

diff --git a/src/src/processrunner.cpp b/src/src/processrunner.cpp
index dc64927..2446f86 100644
--- a/src/src/processrunner.cpp
+++ b/src/src/processrunner.cpp
@@ -497,6 +497,64 @@ QString readProcComm(pid_t pid) {
   return QString::fromUtf8(f.readAll()).trimmed();

 }

 

+// Read /proc/<pid>/cmdline (NUL-separated) and return all argv entries.

+QStringList readProcCmdline(pid_t pid) {

+  QFile f(QString("/proc/%1/cmdline").arg(pid));

+  if (!f.open(QIODevice::ReadOnly)) {

+    return {};

+  }

+

+  const QByteArray data = f.readAll();

+  QStringList parts;

+  for (const QByteArray &part : data.split('\0')) {

+    if (!part.isEmpty()) {

+      parts.push_back(QString::fromUtf8(part));

+    }

+  }

+  return parts;

+}

+

+// Check whether any of the expected executable names appear in a process's

+// comm or cmdline.  Wine processes often show "wine64-preload" or "start.exe"

+// in /proc/comm while the actual game executable only appears in cmdline.

+// Also handles the 15-char TASK_COMM_LEN truncation in /proc/comm.

+bool processMatchesExpected(pid_t pid, const QStringList &expected,

+                            QString *matchedNameOut) {

+  // 1. Check /proc/comm (fast path).

+  const QString comm = readProcComm(pid);

+  if (!comm.isEmpty()) {

+    const QString lower = comm.toLower();

+    for (const QString &exp : expected) {

+      if (lower == exp) {

+        if (matchedNameOut) *matchedNameOut = comm;

+        return true;

+      }

+      // Handle TASK_COMM_LEN truncation (15 chars): if the expected name

+      // is longer than 15 chars, check if comm matches its first 15 chars.

+      if (exp.size() > 15 && lower == exp.left(15)) {

+        if (matchedNameOut) *matchedNameOut = exp;

+        return true;

+      }

+    }

+  }

+

+  // 2. Check /proc/cmdline — Wine/Proton processes carry the .exe name here

+  //    even when comm shows wine64-preloader or start.exe.

+  const QStringList cmdline = readProcCmdline(pid);

+  for (const QString &arg : cmdline) {

+    // Extract just the filename from paths like

+    // "c:\windows\system32\start.exe" or "/home/.../FalloutNV.exe"

+    const QString normalized = QString(arg).replace('\\', '/');

+    const QString base = QFileInfo(normalized).fileName().toLower();

+    if (expected.contains(base)) {

+      if (matchedNameOut) *matchedNameOut = QFileInfo(normalized).fileName();

+      return true;

+    }

+  }

+

+  return false;

+}

+

 std::unordered_map<pid_t, std::vector<pid_t>> buildProcChildrenMap() {

   std::unordered_map<pid_t, std::vector<pid_t>> children;

   DIR *proc = opendir("/proc");

@@ -605,14 +663,10 @@ pid_t findTrackedProcess(pid_t rootPid, const QStringList &expected,
   pid_t best = 0;

   QString bestName;

   for (pid_t pid : descendants) {

-    const QString comm = readProcComm(pid);

-    if (comm.isEmpty()) {

-      continue;

-    }

-    const QString lower = comm.toLower();

-    if (expected.contains(lower)) {

+    QString matched;

+    if (processMatchesExpected(pid, expected, &matched)) {

       best = pid;

-      bestName = comm;

+      bestName = matched;

       break;

     }

   }