From 83a395a162a5c38b899234282996ffafb106daf0 Mon Sep 17 00:00:00 2001
From: BDisp <bd.bdisp@gmail.com>
Date: Wed, 22 Apr 2026 21:36:31 +0100
Subject: [PATCH] Fixes #5057. Pressing `Alt-T` in a `TextField` causes a `t`
 to be entered

---
 .../AnsiHandling/KittyKeyboardPattern.cs      | 12 +++++++++++-
 .../AnsiHandling/KittyKeyboardParsingTests.cs | 13 +++++++++++++
 .../Views/TextFieldTests.cs                   | 19 +++++++++++++++++++
 3 files changed, 43 insertions(+), 1 deletion(-)

diff --git a/Terminal.Gui/Drivers/AnsiHandling/KittyKeyboardPattern.cs b/Terminal.Gui/Drivers/AnsiHandling/KittyKeyboardPattern.cs
index 925849d8f8..25182559c7 100644
--- a/Terminal.Gui/Drivers/AnsiHandling/KittyKeyboardPattern.cs
+++ b/Terminal.Gui/Drivers/AnsiHandling/KittyKeyboardPattern.cs
@@ -128,7 +128,17 @@ public class KittyKeyboardPattern : AnsiKeyboardParserPattern
             (key, modifierField) = NormalizeShiftedPrintableKey (key, modifierField);
         }
 
-        return string.IsNullOrEmpty (modifierField) ? key : ApplyModifiersAndEventType (modifierField, key);
+        if (!string.IsNullOrEmpty (modifierField))
+        {
+            key = ApplyModifiersAndEventType (modifierField, key);
+        }
+
+        if ((key.IsAlt || key.IsCtrl) && !string.IsNullOrEmpty (key.AssociatedText))
+        {
+            key = new Key (key) { AssociatedText = string.Empty };
+        }
+
+        return key;
     }
 
     private static string ParseAssociatedText (string textField)
diff --git a/Tests/UnitTestsParallelizable/Drivers/AnsiHandling/KittyKeyboardParsingTests.cs b/Tests/UnitTestsParallelizable/Drivers/AnsiHandling/KittyKeyboardParsingTests.cs
index 6ba6d25680..b5aea2dde8 100644
--- a/Tests/UnitTestsParallelizable/Drivers/AnsiHandling/KittyKeyboardParsingTests.cs
+++ b/Tests/UnitTestsParallelizable/Drivers/AnsiHandling/KittyKeyboardParsingTests.cs
@@ -499,6 +499,19 @@ public void KittyPattern_AssociatedText_ShiftedPrintableKey ()
         Assert.Equal ("!", key.GetPrintableText ());
     }
 
+    [Fact]
+    public void KittyPattern_AssociatedText_AltModifiedPrintableKey_IsSuppressed ()
+    {
+        // ESC[116;3;116u = Alt+t with associated text 't'
+        Key? key = _pattern.GetKey ("\u001b[116;3;116u");
+
+        Assert.NotNull (key);
+        Assert.True (key.IsAlt);
+        Assert.Equal (Key.T.WithAlt.KeyCode, key.KeyCode);
+        Assert.Equal (string.Empty, key.AssociatedText);
+        Assert.Equal (string.Empty, key.GetPrintableText ());
+    }
+
     [Fact]
     public void KittyPattern_AssociatedText_MultipleCodePoints ()
     {
diff --git a/Tests/UnitTestsParallelizable/Views/TextFieldTests.cs b/Tests/UnitTestsParallelizable/Views/TextFieldTests.cs
index 9098025415..58a7854f50 100644
--- a/Tests/UnitTestsParallelizable/Views/TextFieldTests.cs
+++ b/Tests/UnitTestsParallelizable/Views/TextFieldTests.cs
@@ -355,6 +355,25 @@ public void KittyAltGr2_InsertsAtSign ()
         top.Dispose ();
     }
 
+    [Fact]
+    public void KittyAltModifiedPrintableKey_DoesNotInsertAssociatedText ()
+    {
+        Runnable top = new ();
+        TextField tf = new () { Width = 10 };
+        top.Add (tf);
+        tf.SetFocus ();
+        tf.ClearAllSelection ();
+        tf.InsertionPoint = 0;
+
+        Key? key = new KittyKeyboardPattern ().GetKey ("\u001b[116;3;116u");
+
+        Assert.NotNull (key);
+        Assert.False (top.NewKeyDownEvent (key));
+        Assert.Equal (string.Empty, tf.Text);
+
+        top.Dispose ();
+    }
+
     [Fact]
     public void ShiftedDigitKey_WithoutKittyMetadata_InsertsBaseDigit ()
     {