From e27e865fec1726d1580e5e2c65a60f5a8c4e3bc3 Mon Sep 17 00:00:00 2001
From: BDisp <bd.bdisp@gmail.com>
Date: Mon, 4 Dec 2023 15:07:07 +0000
Subject: [PATCH] Prevents a user to set TextDirection to -1.

---
 Terminal.Gui/Text/TextFormatter.cs   |  4 ++++
 UnitTests/Text/TextFormatterTests.cs | 16 ++++++++++++++
 UnitTests/View/ViewTests.cs          | 33 ++++++++++++++++++++++++++++
 3 files changed, 53 insertions(+)

diff --git a/Terminal.Gui/Text/TextFormatter.cs b/Terminal.Gui/Text/TextFormatter.cs
index 62406b157..751d5b2ee 100644
--- a/Terminal.Gui/Text/TextFormatter.cs
+++ b/Terminal.Gui/Text/TextFormatter.cs
@@ -1139,6 +1139,10 @@ namespace Terminal.Gui {
 		public TextDirection Direction {
 			get => _textDirection;
 			set {
+				if (value == (TextDirection)(-1)) {
+					return;
+				}
+
 				var directionWasIndef = _textDirection == (TextDirection)(-1);
 				_textDirection = EnableNeedsFormat (value);
 				if (directionWasIndef || (AutoSize && Alignment != TextAlignment.Justified && VerticalAlignment != VerticalTextAlignment.Justified)) {
diff --git a/UnitTests/Text/TextFormatterTests.cs b/UnitTests/Text/TextFormatterTests.cs
index e37f18e3f..5370b7fdf 100644
--- a/UnitTests/Text/TextFormatterTests.cs
+++ b/UnitTests/Text/TextFormatterTests.cs
@@ -1794,5 +1794,21 @@ ssb
 
 			driver.End ();
 		}
+
+		[Fact]
+		public void TextDirection_Only_Can_Be_Set_To_Minus_One_On_The_Private_Field ()
+		{
+			var tf = new TextFormatter () { Direction = (TextDirection)(-1) };
+			// There was no change here because it's the same value
+			Assert.Equal ((TextDirection)(-1), tf.Direction);
+
+			// Add a valid value
+			tf.Direction = TextDirection.TopBottom_LeftRight;
+			Assert.Equal (TextDirection.TopBottom_LeftRight, tf.Direction);
+
+			// Add a invalid value
+			tf.Direction = (TextDirection)(-1);
+			Assert.Equal (TextDirection.TopBottom_LeftRight, tf.Direction);
+		}
 	}
 }
\ No newline at end of file
diff --git a/UnitTests/View/ViewTests.cs b/UnitTests/View/ViewTests.cs
index c31b5dff6..c89e426c9 100644
--- a/UnitTests/View/ViewTests.cs
+++ b/UnitTests/View/ViewTests.cs
@@ -1562,5 +1562,38 @@ At 0,0
 			var pos = TestHelpers.AssertDriverContentsWithFrameAre (expected, output);
 			Assert.Equal (new Rect (0, 0, 9, height + 2), pos);
 		}
+
+		[Fact]
+		public void TextDirection_Only_Can_Be_Set_To_Minus_One_On_The_Private_Field ()
+		{
+			var view = new View () { TextDirection = (TextDirection)(-1) };
+			// There was no change here because it's the same value
+			Assert.Equal ((TextDirection)(-1), view.TextDirection);
+
+			// Add a valid value
+			view.TextDirection = TextDirection.TopBottom_LeftRight;
+			Assert.Equal (TextDirection.TopBottom_LeftRight, view.TextDirection);
+
+			// Add a invalid value
+			view.TextDirection = (TextDirection)(-1);
+			Assert.Equal (TextDirection.TopBottom_LeftRight, view.TextDirection);
+
+			view = new View ();
+			// It's the default value
+			Assert.Equal ((TextDirection)(-1), view.TextDirection);
+
+			var container = new View ();
+			container.Add (view);
+			// It's the default value after added
+			Assert.Equal (TextDirection.LeftRight_TopBottom, view.TextDirection);
+
+			view = new View ();
+			// It's the default value
+			Assert.Equal ((TextDirection)(-1), view.TextDirection);
+
+			view.BeginInit ();
+			// It's the default value after initialized
+			Assert.Equal (TextDirection.LeftRight_TopBottom, view.TextDirection);
+		}
 	}
 }