ha it works.

OpenConsole.sln

@@ -12,6 +12,7 @@ Project("{C7167F0D-BC9F-4E6E-AFE1-012C56B48DB5}") = "CascadiaPackage", "src\casc
 EndProject
 Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "Host.EXE", "src\host\exe\Host.EXE.vcxproj", "{9CBD7DFA-1754-4A9D-93D7-857A9D17CB1B}"
 	ProjectSection(ProjectDependencies) = postProject
+		{E437B604-3E98-4F40-A927-E173E818EA4B} = {E437B604-3E98-4F40-A927-E173E818EA4B}
 		{0CF235BD-2DA0-407E-90EE-C467E8BBC714} = {0CF235BD-2DA0-407E-90EE-C467E8BBC714}
 	EndProjectSection
 EndProject
@@ -87,8 +88,8 @@ Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "Host.Tests.Feature", "src\h
 	ProjectSection(ProjectDependencies) = postProject
 		{18D09A24-8240-42D6-8CB6-236EEE820263} = {18D09A24-8240-42D6-8CB6-236EEE820263}
 		{FC802440-AD6A-4919-8F2C-7701F2B38D79} = {FC802440-AD6A-4919-8F2C-7701F2B38D79}
-		{9CBD7DFA-1754-4A9D-93D7-857A9D17CB1B} = {9CBD7DFA-1754-4A9D-93D7-857A9D17CB1B}
 		{58A03BB2-DF5A-4B66-91A0-7EF3BA01269A} = {58A03BB2-DF5A-4B66-91A0-7EF3BA01269A}
+		{9CBD7DFA-1754-4A9D-93D7-857A9D17CB1B} = {9CBD7DFA-1754-4A9D-93D7-857A9D17CB1B}
 	EndProjectSection
 EndProject
 Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "TerminalParser.UnitTests", "src\terminal\parser\ut_parser\Parser.UnitTests.vcxproj", "{12144E07-FE63-4D33-9231-748B8D8C3792}"

src/host/srvinit.cpp

@@ -258,7 +258,8 @@ void ConsoleCheckDebug()
 
 HRESULT ConsoleEstablishHandoff(_In_ HANDLE Server,
                                 const ConsoleArguments* const args, // this can't stay like this because ConsoleArguments could change...
-                                HANDLE driverInputEvent)
+                                HANDLE driverInputEvent,
+                                PCONSOLE_API_MSG connectMessage)
 {
     auto& g = ServiceLocator::LocateGlobals();
     g.handoffTarget = true;
@@ -269,7 +270,7 @@ HRESULT ConsoleEstablishHandoff(_In_ HANDLE Server,
     // Store the driver input event. It's already been told that it exists by whomever started us.
     g.hInputEvent.reset(driverInputEvent);
 
-    HANDLE const hThread = CreateThread(nullptr, 0, ConsoleIoThread, nullptr, 0, nullptr);
+    HANDLE const hThread = CreateThread(nullptr, 0, ConsoleIoThread, connectMessage, 0, nullptr);
     RETURN_HR_IF(E_HANDLE, hThread == nullptr);
     LOG_IF_WIN32_BOOL_FALSE(CloseHandle(hThread)); // The thread will run on its own and close itself. Free the associated handle.
 
@@ -286,11 +287,6 @@ HRESULT ConsoleEstablishHandoff(_In_ HANDLE Server,
     return S_OK;
 }
 
-[[nodiscard]] bool TestFunc()
-{
-    return false;
-}
-
 [[nodiscard]] HRESULT ConsoleCreateIoThreadLegacy(_In_ HANDLE Server, const ConsoleArguments* const args)
 {
     auto& g = ServiceLocator::LocateGlobals();
@@ -688,10 +684,10 @@ PWSTR TranslateConsoleTitle(_In_ PCWSTR pwszConsoleTitle, const BOOL fUnexpand,
 // - This routine is the main one in the console server IO thread.
 // - It reads IO requests submitted by clients through the driver, services and completes them in a loop.
 // Arguments:
-// - <none>
+// - lpParameter - PCONSOLE_API_MSG being handed off to us from the previous I/O.
 // Return Value:
 // - This routine never returns. The process exits when no more references or clients exist.
-DWORD WINAPI ConsoleIoThread(LPVOID /*lpParameter*/)
+DWORD WINAPI ConsoleIoThread(LPVOID lpParameter)
 {
     auto& globals = ServiceLocator::LocateGlobals();
 
@@ -700,6 +696,15 @@ DWORD WINAPI ConsoleIoThread(LPVOID /*lpParameter*/)
     ReceiveMsg._pDeviceComm = globals.pDeviceComm;
     PCONSOLE_API_MSG ReplyMsg = nullptr;
 
+    // If we were given a message on startup, process that in our context and then continue with the IO loop normally.
+    if (lpParameter)
+    {
+        ReceiveMsg = *(PCONSOLE_API_MSG)lpParameter;
+        ReceiveMsg._pApiRoutines = &globals.api;
+        ReceiveMsg._pDeviceComm = globals.pDeviceComm;
+        IoSorter::ServiceIoOperation(&ReceiveMsg, &ReplyMsg);
+    }
+
     bool fShouldExit = false;
     while (!fShouldExit)
     {

src/host/srvinit.h

@@ -30,8 +30,7 @@ PWSTR TranslateConsoleTitle(_In_ PCWSTR pwszConsoleTitle, const BOOL fUnexpand,
 
 extern "C" __declspec(dllexport) HRESULT ConsoleEstablishHandoff(_In_ HANDLE Server,
                                                                  const ConsoleArguments* const args, // this can't stay like this because ConsoleArguments could change...
-                                                                 HANDLE driverInputEvent);
-
-extern "C" __declspec(dllexport) bool TestFunc();
+                                                                 HANDLE driverInputEvent,
+                                                                 PCONSOLE_API_MSG connectMessage);
 
 void ConsoleCheckDebug();

src/server/IoDispatchers.cpp

@@ -165,16 +165,16 @@ PCONSOLE_API_MSG IoDispatchers::ConsoleHandleConnectionRequest(_In_ PCONSOLE_API
 
         typedef HRESULT (*PFNHANDOFF)(HANDLE,
                                       const ConsoleArguments* const, // this can't stay like this because ConsoleArguments could change...
-                                      HANDLE);
+                                      HANDLE,
+                                      PCONSOLE_API_MSG);
 
         typedef bool (*PFNTEST)();
 
         HMODULE mod = LoadLibraryW(L"OpenConsoleDll.dll");
         PFNHANDOFF addr = (PFNHANDOFF)GetProcAddress(mod, "ConsoleEstablishHandoff");
         /*PFNTEST addr = (PFNTEST)GetProcAddress(mod, "TestFunc");*/
-        HRESULT res = addr(Globals.pDeviceComm->_Server.get(), &Globals.launchArgs, Globals.hInputEvent.get());
-        res;
-        if (res)
+        HRESULT res = addr(Globals.pDeviceComm->_Server.get(), &Globals.launchArgs, Globals.hInputEvent.get(), pReceiveMsg);
+        if (res == S_OK)
         {
             Sleep(INFINITE);
             auto rect = til::rectangle{};