Fix: backslash with real newline in short literal doesn't work

src/Lua/CodeAnalysis/Syntax/Lexer.cs

@@ -324,7 +324,13 @@ public bool MoveNext()
                 if (c is '\\')
                 {
                     Advance(1);
+
                     if (span.Length <= offset) break;
+                    if (span[offset] == '\r')
+                    {
+                        if (span.Length<=offset +1) continue;
+                        if (span[offset+1] == '\n')Advance(1);
+                    }
                 }
                 else if (c == quote)
                 {
@@ -530,8 +536,8 @@ void ReadNumber(ref ReadOnlySpan<char> span, ref int offset, out int readCount)
     static bool IsIdentifier(char c)
     {
         return c == '_' ||
-            ('A' <= c && c <= 'Z') ||
-            ('a' <= c && c <= 'z') ||
-            StringHelper.IsNumber(c);
+               ('A' <= c && c <= 'Z') ||
+               ('a' <= c && c <= 'z') ||
+               StringHelper.IsNumber(c);
     }
-}
+}

src/Lua/Internal/StringHelper.cs

@@ -37,7 +37,7 @@ public static bool TryFromStringLiteral(ReadOnlySpan<char> literal, [NotNullWhen
                         builder.Append('\n');
                         break;
                     case '\r':
-                        builder.Append('\r');
+                        builder.Append('\n');
                         // check CRLF
                         if (i + 1 < literal.Length && literal[i + 1] is '\n')
                         {
@@ -306,6 +306,7 @@ public static Regex ToRegex(ReadOnlySpan<char> pattern)
                             builder.Append(c);
                             break;
                     }
+
                     isEscapeSequence = false;
                 }
             }
@@ -358,7 +359,7 @@ public static bool IsNumber(char c)
     public static bool IsDigit(char c)
     {
         return IsNumber(c) ||
-            ('a' <= c && c <= 'f') ||
-            ('A' <= c && c <= 'F');
+               ('a' <= c && c <= 'f') ||
+               ('A' <= c && c <= 'F');
     }
 }

tests/Lua.Tests/StringTests.cs

@@ -0,0 +1,17 @@
+using Lua.CodeAnalysis.Syntax;
+using Lua.CodeAnalysis.Syntax.Nodes;
+
+namespace Lua.Tests;
+
+public class StringTests
+{
+    [TestCase("\r")]
+    [TestCase("\n")]
+    [TestCase("\r\n")]
+    public async Task Test_ShortString_RealNewLine(string newLine)
+    {
+        var result = await LuaState.Create().DoStringAsync($"return \"\\{newLine}\"");
+        Assert.That(result, Has.Length.EqualTo(1));
+        Assert.That(result[0], Is.EqualTo(new LuaValue("\n")));
+    }
+}