From 28295f59122e70102ec5e228535dd2d29b6c857b Mon Sep 17 00:00:00 2001
From: Tom Butcher <tom@tombutcher.work>
Date: Sun, 9 Aug 2026 10:37:02 +0100
Subject: [PATCH] Enhance Windows installer with parent process ID handling for
 improved update reliability
MIME-Version: 1.0
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- Introduced a new variable to capture the parent process ID, allowing the installer to wait for the exact updater process instead of relying on executable names.
- Updated the `restartFarmControlAfterUpdate` function to handle the new parent PID, ensuring a more reliable shutdown of the Farm Control application during updates.
- Modified the `launchWindowsInstaller` function to pass the current process ID as an argument, enhancing the installer’s ability to manage application restarts effectively.
---
 packaging/windows/installer.nsh | 60 ++++++++++++++++++++++++++-------
 src/desktop/winappupdate.js     |  9 ++++-
 2 files changed, 56 insertions(+), 13 deletions(-)

diff --git a/packaging/windows/installer.nsh b/packaging/windows/installer.nsh
index 576eb06..898bb6b 100644
--- a/packaging/windows/installer.nsh
+++ b/packaging/windows/installer.nsh
@@ -6,6 +6,7 @@ Var ProgressLogFile
 Var IsInAppUpdate
 Var RestartAfterInstall
 Var FinalInstDir
+Var UpdateParentPid
 
 ; Generate an include at compile time that defines APP_COPY_TOTAL_BYTES and
 ; copyApplicationFilesWithProgress. The generated macro contains one File
@@ -23,6 +24,7 @@ Var FinalInstDir
   StrCpy $IsInAppUpdate "0"
   StrCpy $RestartAfterInstall "0"
   StrCpy $FinalInstDir ""
+  StrCpy $UpdateParentPid "0"
 
   ${GetParameters} $R9
 
@@ -38,6 +40,13 @@ Var FinalInstDir
     StrCpy $RestartAfterInstall "1"
   ${EndIf}
 
+  ClearErrors
+  ${GetOptions} $R9 "/PARENTPID=" $R8
+  ${IfNot} ${Errors}
+    ; Convert to an integer before it is used in Win32 calls or taskkill.
+    IntOp $UpdateParentPid $R8 + 0
+  ${EndIf}
+
   ; Prefer env var so paths with spaces are reliable; /LOG= remains supported.
   ReadEnvStr $ProgressLogFile "FARMCONTROL_INSTALL_LOG"
   ${If} $ProgressLogFile == ""
@@ -330,22 +339,49 @@ Function restartFarmControlAfterUpdate
   !insertmacro progressSuccess
 
   !insertmacro progressStatus "Waiting for Farm Control to close..."
-  Sleep 2000
 
-  restart_wait_loop:
-    ExecWait 'cmd.exe /c tasklist /FI "IMAGENAME eq FarmControl.exe" 2>nul | find /I "FarmControl.exe"' $R0
-    ${If} $R0 == 0
-      Sleep 1500
-      Goto restart_wait_loop
-    ${EndIf}
-    ExecWait 'cmd.exe /c tasklist /FI "IMAGENAME eq launcher.exe" 2>nul | find /I "launcher.exe"' $R0
-    ${If} $R0 == 0
-      Sleep 1500
-      Goto restart_wait_loop
+  ${If} $UpdateParentPid > 0
+    ; Wait for the exact updater process rather than an executable name. CEF
+    ; builds can keep bun/renderer processes alive after the launcher exits.
+    System::Call 'kernel32::OpenProcess(i 0x00100000, i 0, i $UpdateParentPid) p .r0'
+    ${If} $0 != 0
+      ; Allow two minutes for a graceful CEF shutdown.
+      System::Call 'kernel32::WaitForSingleObject(p r0, i 120000) i .r1'
+      System::Call 'kernel32::CloseHandle(p r0)'
+
+      ${If} $1 == 258
+        !insertmacro progressStatus "Farm Control is taking too long to close; forcing shutdown..."
+        DetailPrint "Farm Control process $UpdateParentPid did not exit; terminating its process tree..."
+        ExecWait 'taskkill /F /T /PID $UpdateParentPid' $R0
+      ${EndIf}
     ${EndIf}
+  ${Else}
+    ; Compatibility fallback for manually launched older installers.
+    StrCpy $R7 0
+    restart_wait_loop:
+      ExecWait 'cmd.exe /c tasklist /FI "IMAGENAME eq FarmControl.exe" 2>nul | find /I "FarmControl.exe"' $R0
+      ${If} $R0 != 0
+        ExecWait 'cmd.exe /c tasklist /FI "IMAGENAME eq launcher.exe" 2>nul | find /I "launcher.exe"' $R0
+      ${EndIf}
+      ${If} $R0 != 0
+        Goto restart_wait_done
+      ${EndIf}
+
+      IntOp $R7 $R7 + 1
+      ${If} $R7 < 80
+        Sleep 1500
+        Goto restart_wait_loop
+      ${EndIf}
+
+      !insertmacro progressStatus "Farm Control is taking too long to close; forcing shutdown..."
+      !insertmacro quitFarmControl
+  ${EndIf}
+
+  restart_wait_done:
+    ; Give CEF descendants a moment to release DLLs before renaming the tree.
+    Sleep 3000
 
   ${If} $IsInAppUpdate == "1"
-    Sleep 1000
     !insertmacro swapUpdateStaging
   ${EndIf}
 
diff --git a/src/desktop/winappupdate.js b/src/desktop/winappupdate.js
index 6cd1c7d..a5b3462 100644
--- a/src/desktop/winappupdate.js
+++ b/src/desktop/winappupdate.js
@@ -262,9 +262,16 @@ export const launchWindowsInstaller = async (
     // /S = silent (https://nsis.sourceforge.io/Reference/SilentInstall)
     // /UPDATE = in-app update (stage into Farm Control.new; swap after exit)
     // /RESTARTFC = installer waits for this process to exit, swaps folders, relaunches
+    // /PARENTPID = exact process to wait for (CEF may outlive the launcher)
     // /LOG= + FARMCONTROL_INSTALL_LOG = progress log
     // (installer:% / PHASE / STATUS / COPY_TOTAL / COPY_FILE)
-    const installerArgs = ['/S', '/UPDATE', '/RESTARTFC', `/LOG=${logPath}`]
+    const installerArgs = [
+      '/S',
+      '/UPDATE',
+      '/RESTARTFC',
+      `/PARENTPID=${process.pid}`,
+      `/LOG=${logPath}`
+    ]
 
     const installerProcess = spawn(resolvedPath, installerArgs, {
       detached: true,