From d024d2aaee75dc57cdadd4597f4e23f7346099da Mon Sep 17 00:00:00 2001
From: Dan Walmsley <dan@walms.co.uk>
Date: Tue, 18 Jan 2022 14:23:54 +0000
Subject: [PATCH] Merge pull request #7374 from
 AvaloniaUI/fixes/5849-textinput-keydown-handed-2

win32: Don't raise TextInput event when KeyDown was handled (Attempt #2)
---
 src/Windows/Avalonia.Win32/WindowImpl.AppWndProc.cs | 13 +++++++++++--
 src/Windows/Avalonia.Win32/WindowImpl.cs            |  1 +
 2 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/src/Windows/Avalonia.Win32/WindowImpl.AppWndProc.cs b/src/Windows/Avalonia.Win32/WindowImpl.AppWndProc.cs
index 89d5009da5..88a0744e3e 100644
--- a/src/Windows/Avalonia.Win32/WindowImpl.AppWndProc.cs
+++ b/src/Windows/Avalonia.Win32/WindowImpl.AppWndProc.cs
@@ -151,8 +151,8 @@ namespace Avalonia.Win32
                     }
                 case WindowsMessage.WM_CHAR:
                     {
-                        // Ignore control chars
-                        if (ToInt32(wParam) >= 32)
+                        // Ignore control chars and chars that were handled in WM_KEYDOWN.
+                        if (ToInt32(wParam) >= 32 && !_ignoreWmChar)
                         {
                             e = new RawTextInputEventArgs(WindowsKeyboardDevice.Instance, timestamp, _owner,
                                 new string((char)ToInt32(wParam), 1));
@@ -519,6 +519,15 @@ namespace Avalonia.Win32
             {
                 Input(e);
 
+                if ((WindowsMessage)msg == WindowsMessage.WM_KEYDOWN)
+                {
+                    // Handling a WM_KEYDOWN message should cause the subsequent WM_CHAR message to
+                    // be ignored. This should be safe to do as WM_CHAR should only be produced in
+                    // response to the call to TranslateMessage/DispatchMessage after a WM_KEYDOWN
+                    // is handled.
+                    _ignoreWmChar = e.Handled;
+                }
+
                 if (e.Handled)
                 {
                     return IntPtr.Zero;
diff --git a/src/Windows/Avalonia.Win32/WindowImpl.cs b/src/Windows/Avalonia.Win32/WindowImpl.cs
index 4c3165eaf9..e4f5268285 100644
--- a/src/Windows/Avalonia.Win32/WindowImpl.cs
+++ b/src/Windows/Avalonia.Win32/WindowImpl.cs
@@ -90,6 +90,7 @@ namespace Avalonia.Win32
         private bool _shown;
         private bool _hiddenWindowIsParent;
         private uint _langid;
+        private bool _ignoreWmChar;
 
         public WindowImpl()
         {