fix missing carriage returns on unix

src/SharpIDE.Godot/Features/TerminalBase/SharpIdeTerminal.cs

@@ -1,3 +1,4 @@
+using System.Buffers;
 using GDExtensionBindgen;
 using Godot;
 
@@ -20,9 +21,21 @@ public partial class SharpIdeTerminal : Control
 	
 	public async Task WriteAsync(byte[] text)
 	{
-		await this.InvokeAsync(() => _terminal.Write(text));
+		var (processedArray, length, wasRented) = ProcessLineEndings(text);
+		try
+		{
+			await this.InvokeAsync(() => _terminal.Write(processedArray.AsSpan(0, length)));
+		}
+		finally
+		{
+			if (wasRented)
+			{
+				ArrayPool<byte>.Shared.Return(processedArray);
+			}
+		}
+		_previousArrayEndedInCr = text.Length > 0 && text[^1] == (byte)'\r';
 	}
-	
+
 	[RequiresGodotUiThread]
 	public void ClearTerminal()
 	{

src/SharpIDE.Godot/Features/TerminalBase/SharpIdeTerminal_LineEndings.cs

@@ -0,0 +1,63 @@
+using System.Buffers;
+
+namespace SharpIDE.Godot.Features.TerminalBase;
+
+public partial class SharpIdeTerminal
+{
+    private bool _previousArrayEndedInCr = false;
+
+    // Unfortunately, although the terminal emulator handles escape sequences etc, it does not handle interpreting \n as \r\n - that is handled by the PTY, which we currently don't use
+    // So we need to replace lone \n with \r\n ourselves
+    // TODO: Probably run processes with PTY instead, so that this is not needed, and so we can capture user input and Ctrl+C etc
+    // 🤖
+    private (byte[] array, int length, bool wasRented) ProcessLineEndings(byte[] input)
+    {
+        if (input.Length == 0) return (input, 0, false);
+
+        // Count how many \n need to be replaced (those not preceded by \r)
+        var replacementCount = 0;
+        var previousWasCr = _previousArrayEndedInCr;
+
+        for (var i = 0; i < input.Length; i++)
+        {
+            if (input[i] == (byte)'\n')
+            {
+                // Check if it's preceded by \r
+                var precededByCr = (i > 0 && input[i - 1] == (byte)'\r') || (i == 0 && previousWasCr);
+                if (!precededByCr)
+                {
+                    replacementCount++;
+                }
+            }
+
+            previousWasCr = input[i] == (byte)'\r';
+        }
+
+        // If no replacements needed, return original array
+        if (replacementCount == 0) return (input, input.Length, false);
+
+        // Rent array from pool with space for additional \r characters
+        var requiredSize = input.Length + replacementCount;
+        var result = ArrayPool<byte>.Shared.Rent(requiredSize);
+        var writeIndex = 0;
+        previousWasCr = _previousArrayEndedInCr;
+
+        for (var i = 0; i < input.Length; i++)
+        {
+            if (input[i] == (byte)'\n')
+            {
+                // Check if it's preceded by \r
+                var precededByCr = (i > 0 && input[i - 1] == (byte)'\r') || (i == 0 && previousWasCr);
+                if (!precededByCr)
+                {
+                    result[writeIndex++] = (byte)'\r';
+                }
+            }
+
+            result[writeIndex++] = input[i];
+            previousWasCr = input[i] == (byte)'\r';
+        }
+
+        return (result, writeIndex, true);
+    }
+}