sync initial state of windw with conpty

src/cascadia/TerminalApp/TerminalPage.cpp

@@ -2422,6 +2422,13 @@ namespace winrt::TerminalApp::implementation
         // create here.
         // TermControl will copy the settings out of the settings passed to it.
         TermControl term{ settings.DefaultSettings(), settings.UnfocusedSettings(), connection };
+
+        // GH#12515: ConPTY assumes it's hidden at the start. If we're not, let it know now.
+        if (_visible)
+        {
+            term.WindowVisibilityChanged(_visible);
+        }
+
         return term;
     }
 
@@ -2797,6 +2804,7 @@ namespace winrt::TerminalApp::implementation
     // - <none>
     void TerminalPage::WindowVisibilityChanged(const bool showOrHide)
     {
+        _visible = showOrHide;
         for (const auto& tab : _tabs)
         {
             if (auto terminalTab{ _GetTerminalTabImpl(tab) })

src/cascadia/TerminalApp/TerminalPage.h

@@ -196,6 +196,7 @@ namespace winrt::TerminalApp::implementation
         std::optional<int> _rearrangeFrom{};
         std::optional<int> _rearrangeTo{};
         bool _removing{ false };
+        bool _visible{ true };
 
         std::vector<std::vector<Microsoft::Terminal::Settings::Model::ActionAndArgs>> _previouslyClosedPanesAndTabs{};
 

src/cascadia/TerminalConnection/ConptyConnection.cpp

@@ -310,6 +310,13 @@ namespace winrt::Microsoft::Terminal::TerminalConnection::implementation
             }
 
             THROW_IF_FAILED(_CreatePseudoConsoleAndPipes(dimensions, flags, &_inPipe, &_outPipe, &_hPC));
+
+            // GH#12515: The conpty assumes it's hidden at the start. If we're visible, let it know now.
+            if (_initialVisibility)
+            {
+                THROW_IF_FAILED(ConptyShowHidePseudoConsole(_hPC.get(), _initialVisibility));
+            }
+
             THROW_IF_FAILED(_LaunchAttachedClient());
         }
         // But if it was an inbound handoff... attempt to synchronize the size of it with what our connection
@@ -484,11 +491,15 @@ namespace winrt::Microsoft::Terminal::TerminalConnection::implementation
 
     void ConptyConnection::ShowHide(const bool show)
     {
-        // If we haven't connected yet, then TODO!
+        // If we haven't connected yet, then stash for when we do connect.
         if (_isConnected())
         {
             THROW_IF_FAILED(ConptyShowHidePseudoConsole(_hPC.get(), show));
         }
+        else
+        {
+            _initialVisibility = show;
+        }
     }
 
     void ConptyConnection::Close() noexcept

src/cascadia/TerminalConnection/ConptyConnection.h

@@ -69,6 +69,7 @@ namespace winrt::Microsoft::Terminal::TerminalConnection::implementation
         hstring _commandline{};
         hstring _startingDirectory{};
         hstring _startingTitle{};
+        bool _initialVisibility{ false };
         Windows::Foundation::Collections::ValueSet _environment{ nullptr };
         guid _guid{}; // A unique session identifier for connected client
         hstring _clientName{}; // The name of the process hosted by this ConPTY connection (as of launch).

src/host/PtySignalInputThread.cpp

@@ -67,6 +67,10 @@ void PtySignalInputThread::ConnectConsole() noexcept
     {
         _DoResizeWindow(*_earlyResize);
     }
+    if (_initialShowHide)
+    {
+        _DoShowHide(_initialShowHide->show);
+    }
 }
 
 // Method Description:
@@ -83,8 +87,8 @@ void PtySignalInputThread::ConnectConsole() noexcept
         {
         case PtySignal::ShowHideWindow:
         {
-            ShowHideData resizeMsg = { 0 };
-            _GetData(&resizeMsg, sizeof(resizeMsg));
+            ShowHideData msg = { 0 };
+            _GetData(&msg, sizeof(msg));
 
             LockConsole();
             auto Unlock = wil::scope_exit([&] { UnlockConsole(); });
@@ -93,10 +97,11 @@ void PtySignalInputThread::ConnectConsole() noexcept
             if (!_consoleConnected)
             {
                 // TODO!
+                _initialShowHide = msg;
             }
             else
             {
-                _DoShowHide(resizeMsg.show);
+                _DoShowHide(msg.show);
             }
             break;
         }

src/host/PtySignalInputThread.hpp

@@ -67,6 +67,7 @@ namespace Microsoft::Console
         DWORD _dwThreadId;
         bool _consoleConnected;
         std::optional<ResizeWindowData> _earlyResize;
+        std::optional<ShowHideData> _initialShowHide;
         std::unique_ptr<Microsoft::Console::VirtualTerminal::ConGetSet> _pConApi;
     };
 }