From 76dab4ad0b8c475784c558526555961c2e703be3 Mon Sep 17 00:00:00 2001
From: Alexandru Ciobanu <alex+git@ciobanu.org>
Date: Wed, 19 Oct 2022 09:37:52 +0100
Subject: [PATCH 1/2] Simplify MakePrintable by using AND and avoiding
 converting to string and back.

---
 Terminal.Gui/Core/ConsoleDriver.cs | 15 +++++----------
 1 file changed, 5 insertions(+), 10 deletions(-)

diff --git a/Terminal.Gui/Core/ConsoleDriver.cs b/Terminal.Gui/Core/ConsoleDriver.cs
index 873d8398b..cd180af1c 100644
--- a/Terminal.Gui/Core/ConsoleDriver.cs
+++ b/Terminal.Gui/Core/ConsoleDriver.cs
@@ -681,11 +681,13 @@ namespace Terminal.Gui {
 		/// <param name="col">Column to move the cursor to.</param>
 		/// <param name="row">Row to move the cursor to.</param>
 		public abstract void Move (int col, int row);
+		
 		/// <summary>
 		/// Adds the specified rune to the display at the current cursor position
 		/// </summary>
 		/// <param name="rune">Rune to add.</param>
 		public abstract void AddRune (Rune rune);
+
 		/// <summary>
 		/// Ensures a Rune is not a control character and can be displayed by translating characters below 0x20
 		/// to equivalent, printable, Unicode chars.
@@ -694,21 +696,14 @@ namespace Terminal.Gui {
 		/// <returns></returns>
 		public static Rune MakePrintable (Rune c)
 		{
-			var controlChars = gethexaformat (c, 4);
-			if (controlChars <= 0x1F || (controlChars >= 0X7F && controlChars <= 0x9F)) {
+			var controlChars = c & 0xFFFF;
+			if (controlChars <= 0x1F || controlChars >= 0X7F && controlChars <= 0x9F) {
 				// ASCII (C0) control characters.
 				// C1 control characters (https://www.aivosto.com/articles/control-characters.html#c1)
 				return new Rune (controlChars + 0x2400);
-			} else {
-				return c;
 			}
-		}
 
-		static uint gethexaformat (uint rune, int length)
-		{
-			var hex = rune.ToString ($"x{length}");
-			var hexstr = hex.Substring (hex.Length - length, length);
-			return (uint)int.Parse (hexstr, System.Globalization.NumberStyles.HexNumber);
+			return c;
 		}
 
 		/// <summary>

From 441960e25ee486f3858d02f5916c591462fefa6e Mon Sep 17 00:00:00 2001
From: Alexandru Ciobanu <alex+git@ciobanu.org>
Date: Wed, 19 Oct 2022 13:41:02 +0100
Subject: [PATCH 2/2] Added two unit tests to check for the MakePrintable
 cases.

---
 UnitTests/ConsoleDriverTests.cs | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/UnitTests/ConsoleDriverTests.cs b/UnitTests/ConsoleDriverTests.cs
index cb4bc1dcf..e9688c638 100644
--- a/UnitTests/ConsoleDriverTests.cs
+++ b/UnitTests/ConsoleDriverTests.cs
@@ -608,5 +608,29 @@ namespace Terminal.Gui.ConsoleDrivers {
 			Application.Run (win);
 			Application.Shutdown ();
 		}
+		
+		[Theory]
+		[InlineData(0x0000001F, 0x241F)]
+		[InlineData(0x0000007F, 0x247F)]
+		[InlineData(0x0000009F, 0x249F)]
+		[InlineData(0x0001001A, 0x241A)]
+		public void MakePrintable_Converts_Control_Chars_To_Proper_Unicode (uint code, uint expected)
+		{
+			var actual = ConsoleDriver.MakePrintable(code);
+				
+			Assert.Equal (expected, actual.Value);
+		}
+		
+		[Theory]
+		[InlineData(0x20)]
+		[InlineData(0x7E)]
+		[InlineData(0xA0)]
+		[InlineData(0x010020)]
+		public void MakePrintable_Does_Not_Convert_Ansi_Chars_To_Unicode (uint code)
+		{
+			var actual = ConsoleDriver.MakePrintable(code);
+				
+			Assert.Equal (code, actual.Value);
+		}
 	}
 }