Fix non-Steam game launch: skip steam bridge, fix process tracking

Set UMU_ID=fluorine when Steam DRM is disabled so Proton-GE launches
the game directly instead of through steam.exe (which asserts for
non-Steam executables like GOG games).

Fix VFS premature shutdown by tracking the game PID across process
reparenting.  When the proton root process exits, wine/game processes
get reparented to PID 1 and disappear from the descendant tree.  Now
we remember the tracked game PID and poll it directly, keeping VFS
mounted until the actual game exits.

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

2 files changed, 43 insertions, 8 deletions

diff --git a/src/src/processrunner.cpp b/src/src/processrunner.cpp
index 892fd79..dc64927 100644
--- a/src/src/processrunner.cpp
+++ b/src/src/processrunner.cpp
@@ -669,6 +669,7 @@ ProcessRunner::Results waitForPid(pid_t pid, LPDWORD exitCode,
   }

 

   bool seenTrackedProcess = false;

+  pid_t lastTrackedPid = 0;

 

   while (true) {

     QString trackedName;

@@ -677,14 +678,25 @@ ProcessRunner::Results waitForPid(pid_t pid, LPDWORD exitCode,
     const pid_t tracked = findTrackedProcess(pid, expected, &trackedName);

     if (tracked > 0) {

       seenTrackedProcess = true;

+      lastTrackedPid = tracked;

       displayPid = tracked;

       displayName = trackedName;

     } else if (seenTrackedProcess) {

-      if (exitCode != nullptr) {

-        *exitCode = 0;

+      // The tracked process is no longer a descendant of the root PID.

+      // This can happen when the root (proton) exits and wine/game processes

+      // get reparented to PID 1.  Before declaring the game exited, check

+      // if the last tracked PID is still alive.

+      if (lastTrackedPid > 0 && ::kill(lastTrackedPid, 0) == 0) {

+        displayPid = lastTrackedPid;

+        displayName = readProcComm(lastTrackedPid);

+        log::debug("tracked process {} reparented but still alive", lastTrackedPid);

+      } else {

+        if (exitCode != nullptr) {

+          *exitCode = 0;

+        }

+        log::debug("tracked child process {} for root {} exited", lastTrackedPid, pid);

+        return ProcessRunner::Completed;

       }

-      log::debug("tracked child process for root {} exited", pid);

-      return ProcessRunner::Completed;

     }

 

     if (ls != nullptr) {

@@ -693,18 +705,23 @@ ProcessRunner::Results waitForPid(pid_t pid, LPDWORD exitCode,
     }

 

     if (useKillPoll) {

-      // Poll for process existence via kill(pid, 0)

-      if (::kill(pid, 0) != 0) {

+      // Poll for process existence via kill(pid, 0).

+      // When we have a tracked game PID, monitor that instead of the root

+      // (proton) PID which may have already exited.

+      const pid_t pollPid = (seenTrackedProcess && lastTrackedPid > 0)

+                                ? lastTrackedPid

+                                : pid;

+      if (::kill(pollPid, 0) != 0) {

         if (errno == ESRCH) {

           if (exitCode != nullptr) {

             *exitCode = 0;

           }

-          log::debug("process {} completed", pid);

+          log::debug("process {} completed", pollPid);

           return ProcessRunner::Completed;

         }

         // EPERM means the process exists but we can't signal it; keep waiting

         else if (errno != EPERM) {

-          log::error("failed checking process {}, errno={}", pid, errno);

+          log::error("failed checking process {}, errno={}", pollPid, errno);

           return ProcessRunner::Error;

         }

       }

@@ -713,6 +730,16 @@ ProcessRunner::Results waitForPid(pid_t pid, LPDWORD exitCode,
       const pid_t waitResult = ::waitpid(pid, &status, WNOHANG);

 

       if (waitResult == pid) {

+        // Root process (proton) exited.  If we have a tracked game process

+        // that is still alive, switch to polling the game PID directly

+        // rather than declaring the game finished.

+        if (seenTrackedProcess && lastTrackedPid > 0 &&

+            ::kill(lastTrackedPid, 0) == 0) {

+          log::debug("root process {} exited but tracked game {} still alive, "

+                     "switching to kill-poll", pid, lastTrackedPid);

+          useKillPoll = true;

+          continue;

+        }

         if (exitCode != nullptr) {

           *exitCode = exitCodeFromWaitStatus(status);

         }

diff --git a/src/src/protonlauncher.cpp b/src/src/protonlauncher.cpp
index 4c5e39a..dbe9e20 100644
--- a/src/src/protonlauncher.cpp
+++ b/src/src/protonlauncher.cpp
@@ -381,6 +381,14 @@ bool ProtonLauncher::launchWithProton(qint64& pid) const
     env.insert("SteamGameId", appId);
   }
 
+  // When Steam DRM is disabled (e.g. GOG games), set UMU_ID so that
+  // Proton-GE skips the built-in steam.exe bridge.  Without this, Proton
+  // tries to initialise the Steam client which causes an assertion failure
+  // for non-Steam executables.
+  if (!m_useSteamDrm) {
+    env.insert("UMU_ID", "fluorine");
+  }
+
   env.insert("DOTNET_ROOT", "");
   env.insert("DOTNET_MULTILEVEL_LOOKUP", "0");