Fix fulltrust process sometimes exiting on start (#9580)

Author: gave92

src/Files.FullTrust/Program.cs

@@ -231,46 +231,27 @@ private static bool HandleCommandLineArgs()
             {
                 localSettings.Values.Remove("Arguments");
 
-                if (arguments == "StartUwp")
+                if (arguments == "TerminateUwp")
                 {
-                    var folder = localSettings.Values.Get("Folder", "");
-                    localSettings.Values.Remove("Folder");
-
-                    using Process process = new Process();
-                    process.StartInfo.UseShellExecute = true;
-                    process.StartInfo.FileName = "files.exe";
-                    process.StartInfo.Arguments = folder;
-                    process.Start();
-
-                    TerminateProcess((int)localSettings.Values["pid"]);
-                    return true;
-                }
-                else if (arguments == "TerminateUwp")
-                {
-                    TerminateProcess((int)localSettings.Values["pid"]);
-                    return true;
+                    // Return false and don't exit if PID process is not running
+                    // Argument may refer to unrelated session (#9580)
+                    return TerminateProcess((int)localSettings.Values["pid"]);
                 }
                 else if (arguments == "ShellCommand")
                 {
-                    TerminateProcess((int)localSettings.Values["pid"]);
-
                     Win32API.OpenFolderInExistingShellWindow((string)localSettings.Values["ShellCommand"]);
 
-                    return true;
+                    return TerminateProcess((int)localSettings.Values["pid"]);
                 }
             }
 
             return false;
         }
 
-        private static void TerminateProcess(int processId)
+        private static bool TerminateProcess(int processId)
         {
             // Kill the process. This is a BRUTAL WAY to kill a process.
-#if DEBUG
-            // In debug mode this kills this process too??
-#else
-            SafetyExtensions.IgnoreExceptions(() => Process.GetProcessById(processId).Kill(), Program.Logger);
-#endif
+            return SafetyExtensions.IgnoreExceptions(() => Process.GetProcessById(processId).Kill());
         }
     }
 }

src/Files.Uwp/Program.cs

@@ -27,7 +27,6 @@ private static async Task Main()
                 if (AppInstance.RecommendedInstance != null)
                 {
                     AppInstance.RecommendedInstance.RedirectActivationTo();
-                    await TerminateUwpAppInstance(proc.Id);
                     return;
                 }
                 else if (activatedArgs is LaunchActivatedEventArgs)
@@ -49,7 +48,6 @@ private static async Task Main()
                             var plInstance = AppInstance.GetInstances().First(x => x.Key.Equals(PrelaunchInstanceKey));
                             ApplicationData.Current.LocalSettings.Values["WAS_PRELAUNCH_INSTANCE_ACTIVATED"] = true;
                             plInstance.RedirectActivationTo();
-                            await TerminateUwpAppInstance(proc.Id);
                             return;
                         }
                         else
@@ -59,7 +57,6 @@ private static async Task Main()
                             if (!instance.IsCurrentInstance && !string.IsNullOrWhiteSpace(launchArgs.Arguments))
                             {
                                 instance.RedirectActivationTo();
-                                await TerminateUwpAppInstance(proc.Id);
                                 return;
                             }
                         }
@@ -75,7 +72,6 @@ private static async Task Main()
                         if (!instance.IsCurrentInstance)
                         {
                             instance.RedirectActivationTo();
-                            await TerminateUwpAppInstance(proc.Id);
                             return;
                         }
                     }
@@ -87,7 +83,6 @@ private static async Task Main()
                     if (!instance.IsCurrentInstance)
                     {
                         instance.RedirectActivationTo();
-                        await TerminateUwpAppInstance(proc.Id);
                         return;
                     }
                 }
@@ -127,6 +122,8 @@ private static async Task Main()
                     if (!instance.IsCurrentInstance)
                     {
                         instance.RedirectActivationTo();
+                        // Terminate "zombie" Files process which remains in suspended state
+                        // after redirection when launched by command line
                         await TerminateUwpAppInstance(proc.Id);
                         return;
                     }
@@ -146,26 +143,6 @@ public static async Task OpenShellCommandInExplorerAsync(string shellCommand, in
             await FullTrustProcessLauncher.LaunchFullTrustProcessForCurrentAppAsync();
         }
 
-        public static async Task SpawnUnelevatedUwpAppInstance(int pid)
-        {
-            IActivatedEventArgs activatedArgs = AppInstance.GetActivatedEventArgs();
-            if (activatedArgs is CommandLineActivatedEventArgs cmdLineArgs)
-            {
-                var parsedCommands = CommandLineParser.ParseUntrustedCommands(cmdLineArgs.Operation.Arguments);
-                switch (parsedCommands.FirstOrDefault()?.Type)
-                {
-                    case ParsedCommandType.ExplorerShellCommand:
-                    case ParsedCommandType.OpenDirectory:
-                    case ParsedCommandType.OpenPath:
-                        ApplicationData.Current.LocalSettings.Values["Folder"] = parsedCommands[0].Payload;
-                        break;
-                }
-            }
-            ApplicationData.Current.LocalSettings.Values["Arguments"] = "StartUwp";
-            ApplicationData.Current.LocalSettings.Values["pid"] = pid;
-            await FullTrustProcessLauncher.LaunchFullTrustProcessForCurrentAppAsync();
-        }
-
         public static async Task TerminateUwpAppInstance(int pid)
         {
             ApplicationData.Current.LocalSettings.Values["Arguments"] = "TerminateUwp";