This makes sure we re-own the window appropriately, but defterm doesn…

…'t request focus mode. Weird.

src/cascadia/TerminalApp/TerminalPage.cpp

@@ -69,6 +69,29 @@ namespace winrt::TerminalApp::implementation
     //   - see GH#2988
     HRESULT TerminalPage::Initialize(HWND hwnd)
     {
+        if (!_hostingHwnd.has_value())
+        {
+            // GH#13211 - if we haven't yet set the owning hwnd, reparent all the controls now.
+            for (const auto& tab : _tabs)
+            {
+                if (auto terminalTab{ _GetTerminalTabImpl(tab) })
+                {
+                    terminalTab->GetRootPane()->WalkTree([&](auto&& pane) {
+                        if (const auto& term{ pane->GetTerminalControl() })
+                        {
+                            term.OwningHwnd(reinterpret_cast<uint64_t>(hwnd));
+                        }
+                    });
+                }
+                // We don't need to worry about resetting the owning hwnd for the
+                // SUI here. GH#13211 only repros for a defterm connection, where
+                // the tab is spawned before the window is created. It's not
+                // possible to make a SUI tab like that, before the window is
+                // created. The SUI could be spawned as a part of a window restore,
+                // but that would still work fine. The window would be created
+                // before restoring previous tabs in that scenario.
+            }
+        }
         _hostingHwnd = hwnd;
         return S_OK;
     }

src/cascadia/TerminalControl/ControlCore.cpp

@@ -267,11 +267,11 @@ namespace winrt::Microsoft::Terminal::Control::implementation
             const auto height = vp.Height();
             _connection.Resize(height, width);
 
-            if (_OwningHwnd != 0)
+            if (_owningHwnd != 0)
             {
                 if (auto conpty{ _connection.try_as<TerminalConnection::ConptyConnection>() })
                 {
-                    conpty.ReparentWindow(_OwningHwnd);
+                    conpty.ReparentWindow(_owningHwnd);
                 }
             }
 
@@ -1854,4 +1854,21 @@ namespace winrt::Microsoft::Terminal::Control::implementation
         // transparency, or our acrylic, or our image.
         return Opacity() < 1.0f || UseAcrylic() || !_settings->BackgroundImage().empty() || _settings->UseBackgroundImageForWindow();
     }
+
+    uint64_t ControlCore::OwningHwnd()
+    {
+        return _owningHwnd;
+    }
+
+    void ControlCore::OwningHwnd(uint64_t owner)
+    {
+        if (owner != _owningHwnd && _connection)
+        {
+            if (auto conpty{ _connection.try_as<TerminalConnection::ConptyConnection>() })
+            {
+                conpty.ReparentWindow(owner);
+            }
+        }
+        _owningHwnd = owner;
+    }
 }

src/cascadia/TerminalControl/ControlCore.h

@@ -179,10 +179,8 @@ namespace winrt::Microsoft::Terminal::Control::implementation
 
         void WindowVisibilityChanged(const bool showOrHide);
 
-        // TODO:GH#1256 - When a tab can be torn out or otherwise reparented to
-        // another window, this value will need a custom setter, so that we can
-        // also update the connection.
-        WINRT_PROPERTY(uint64_t, OwningHwnd, 0);
+        uint64_t OwningHwnd();
+        void OwningHwnd(uint64_t owner);
 
         RUNTIME_SETTING(double, Opacity, _settings->Opacity());
         RUNTIME_SETTING(bool, UseAcrylic, _settings->UseAcrylic());
@@ -252,6 +250,8 @@ namespace winrt::Microsoft::Terminal::Control::implementation
         double _panelHeight{ 0 };
         double _compositionScale{ 0 };
 
+        uint64_t _owningHwnd{ 0 };
+
         winrt::Windows::System::DispatcherQueue _dispatcher{ nullptr };
         std::shared_ptr<ThrottledFuncTrailing<>> _tsfTryRedrawCanvas;
         std::shared_ptr<ThrottledFuncTrailing<>> _updatePatternLocations;