From f50d6d22bdf6d545ee50f74b3a1d4d54f9584259 Mon Sep 17 00:00:00 2001
From: GitHubProUser67 <127040195+GitHubProUser67@users.noreply.github.com>
Date: Wed, 18 Feb 2026 18:17:09 +0100
Subject: [PATCH] Fixes a StackOverflow issue with the Lexer system.

When doing a lua script with a whole lot of comments starting with "--", it will throw a StackOverflow assertion due to excessive amount of MoveNext calls. This commit fixes that bug by manually doing recursive jobs.
---
 src/Lua/CodeAnalysis/Syntax/Lexer.cs | 38 ++++++++++++++++++++--------
 1 file changed, 27 insertions(+), 11 deletions(-)

diff --git a/src/Lua/CodeAnalysis/Syntax/Lexer.cs b/src/Lua/CodeAnalysis/Syntax/Lexer.cs
index 322e7c01..5faf57c7 100644
--- a/src/Lua/CodeAnalysis/Syntax/Lexer.cs
+++ b/src/Lua/CodeAnalysis/Syntax/Lexer.cs
@@ -79,6 +79,11 @@ public bool MoveNext()
         {
             case ' ':
             case '\t':
+                while (offset < Source.Length && (Source.Span[offset] == ' ' || Source.Span[offset] == '\t'))
+                {
+                    Advance(1);
+                }
+
                 return MoveNext();
             case '\n':
                 current = SyntaxToken.EndOfLine(position);
@@ -110,16 +115,16 @@ public bool MoveNext()
                 current = SyntaxToken.Addition(position);
                 return true;
             case '-':
-                // comment
-                if (c2 == '-')
+                // handle comments iteratively
+                while (offset < span.Length && c2 == '-')
                 {
                     var pos = position;
-                    Advance(1);
+                    Advance(1); // consume first '-'
 
                     // block comment
-                    if (span.Length > offset + 1 && span[offset] is '[' && span[offset + 1] is '[' or '=')
+                    if (span.Length > offset + 1 && span[offset] == '[' && (span[offset + 1] == '[' || span[offset + 1] == '='))
                     {
-                        Advance(1);
+                        Advance(1); // consume second '-'
                         var (_, _, isTerminated) = ReadUntilLongBracketEnd(ref span);
                         if (!isTerminated)
                         {
@@ -131,13 +136,24 @@ public bool MoveNext()
                         ReadUntilEOL(ref span, ref offset, out _);
                     }
 
-                    return MoveNext();
-                }
-                else
-                {
-                    current = SyntaxToken.Subtraction(position);
-                    return true;
+                    // prepare for next iteration
+                    if (offset < span.Length)
+                    {
+                        c2 = (offset + 1 < span.Length) ? span[offset + 1] : char.MinValue;
+                        if (span[offset] != '-') break; // next char is not a comment, exit loop
+                    }
+                    else
+                    {
+                        break;
+                    }
                 }
+
+                // after skipping comments, if we reached end, return false
+                if (offset >= span.Length)
+                    return false;
+
+                current = SyntaxToken.Subtraction(position); // if single '-' remains
+                return true;
             case '*':
                 current = SyntaxToken.Multiplication(position);
                 return true;