From 1fe0e593ec5176ba26a9021fbecb8c98711ceb65 Mon Sep 17 00:00:00 2001
From: Akeit0 <90429982+Akeit0@users.noreply.github.com>
Date: Thu, 17 Apr 2025 00:23:00 +0900
Subject: [PATCH 1/2] Fix: invariant culture in not used in string.format

---
 src/Lua/Standard/StringLibrary.cs | 19 ++++++++++---------
 1 file changed, 10 insertions(+), 9 deletions(-)

diff --git a/src/Lua/Standard/StringLibrary.cs b/src/Lua/Standard/StringLibrary.cs
index 996adf82..e92702c7 100644
--- a/src/Lua/Standard/StringLibrary.cs
+++ b/src/Lua/Standard/StringLibrary.cs
@@ -2,6 +2,7 @@
 using System.Text.RegularExpressions;
 using Lua.Internal;
 using Lua.Runtime;
+using System.Globalization;
 
 namespace Lua.Standard;
 
@@ -259,23 +260,23 @@ public async ValueTask<int> Format(LuaFunctionExecutionContext context, Memory<L
                         {
                             case 'f':
                                 formattedValue = precision < 0
-                                    ? f.ToString()
-                                    : f.ToString($"F{precision}");
+                                    ? f.ToString(CultureInfo.InvariantCulture)
+                                    : f.ToString($"F{precision}",CultureInfo.InvariantCulture);
                                 break;
                             case 'e':
                                 formattedValue = precision < 0
-                                    ? f.ToString()
-                                    : f.ToString($"E{precision}");
+                                    ? f.ToString(CultureInfo.InvariantCulture)
+                                    : f.ToString($"E{precision}",CultureInfo.InvariantCulture);
                                 break;
                             case 'g':
                                 formattedValue = precision < 0
-                                    ? f.ToString()
-                                    : f.ToString($"G{precision}");
+                                    ? f.ToString(CultureInfo.InvariantCulture)
+                                    : f.ToString($"G{precision}",CultureInfo.InvariantCulture);
                                 break;
                             case 'G':
                                 formattedValue = precision < 0
-                                    ? f.ToString().ToUpper()
-                                    : f.ToString($"G{precision}").ToUpper();
+                                    ? f.ToString(CultureInfo.InvariantCulture).ToUpper()
+                                    : f.ToString($"G{precision}",CultureInfo.InvariantCulture).ToUpper();
                                 break;
                         }
 
@@ -310,7 +311,7 @@ public async ValueTask<int> Format(LuaFunctionExecutionContext context, Memory<L
                                 break;
                             case LuaValueType.Number:
                                 // TODO: floating point numbers must be in hexadecimal notation
-                                formattedValue = parameter.Read<double>().ToString();
+                                formattedValue = parameter.Read<double>().ToString(CultureInfo.InvariantCulture);
                                 break;
                             default:
                                 using (var strBuffer = new PooledArray<LuaValue>(1))

From 365f352d03befab2ba55740eee2dd8574fc2212d Mon Sep 17 00:00:00 2001
From: Akeit0 <90429982+Akeit0@users.noreply.github.com>
Date: Thu, 17 Apr 2025 00:36:13 +0900
Subject: [PATCH 2/2] Add: test of string.format with noninvariant culture

---
 tests/Lua.Tests/StringTests.cs | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/tests/Lua.Tests/StringTests.cs b/tests/Lua.Tests/StringTests.cs
index 921205d0..93bea036 100644
--- a/tests/Lua.Tests/StringTests.cs
+++ b/tests/Lua.Tests/StringTests.cs
@@ -1,5 +1,7 @@
 using Lua.CodeAnalysis.Syntax;
 using Lua.CodeAnalysis.Syntax.Nodes;
+using Lua.Standard;
+using System.Globalization;
 
 namespace Lua.Tests;
 
@@ -14,4 +16,16 @@ public async Task Test_ShortString_RealNewLine(string newLine)
         Assert.That(result, Has.Length.EqualTo(1));
         Assert.That(result[0], Is.EqualTo(new LuaValue("\n")));
     }
+
+    [TestCase("fr-FR")]
+    public async Task Test_StringFormat_Culture(string newLine)
+    {
+        var state = LuaState.Create();
+        state.OpenBasicLibrary();
+        state.OpenStringLibrary();
+        var culture = CultureInfo.CurrentCulture;
+        CultureInfo.CurrentCulture = CultureInfo.GetCultureInfo(newLine);
+        await state.DoStringAsync($"""assert(tonumber(string.format("%f", 10.3)) == 10.3)""");
+        CultureInfo.CurrentCulture = culture;
+    }
 }
\ No newline at end of file