String comparison regression bug

[clement911]

Description

The String comparison logic returns incorrect result for some string.

Reproduction Steps

using System;
using System.Globalization;

public class Program
{
   public static void Main()
   {
       Console.WriteLine(new CultureInfo("en-US").CompareInfo.Compare("ʻ", "", CompareOptions.IgnoreNonSpace));
   }
}

Expected behavior

Console prints 0

Actual behavior

Console prints 1

Regression?

It's a regression.
It works fine in .NET framework 4.7.2 so it appears the bug is limited to .NET core

Known Workarounds

None that I'm aware of.

Configuration

.NET 8 Windows x64

Other information

This seems to be a regression. It works in .NET framework but not .NET core

[ghost]

Tagging subscribers to this area: @DavoudEshtehari, @David-Engel, @JRahnama
See info in area-owners.md if you want to be subscribed.

Issue Details

---

Description

The SqlString class comparison logic returns incorrect result for some string.

Reproduction Steps

using System;
using System.Linq;
using System.Data.SqlTypes;

public class Program
{
	public static void Main()
	{
		 var sqlCompareOptions = SqlCompareOptions.IgnoreCase | SqlCompareOptions.IgnoreNonSpace | SqlCompareOptions.IgnoreKanaType | SqlCompareOptions.IgnoreWidth;
 		 var res = new SqlString("ʻ", 1033, sqlCompareOptions) == new SqlString("", 1033, sqlCompareOptions);
		 Console.WriteLine(res);
	}
}

Expected behavior

Console prints True

Actual behavior

Console prints False

Regression?

It's a regression.
It works fine in .NET framework 4.7.2 so it appears the bug is limited to .NET core

Known Workarounds

None that I'm aware of.

Configuration

.NET 8 Windows x64

Other information

This seems to be a regression. It works in .NET framework but not .NET core

Author:	clement911
Assignees:	-
Labels:	area-System.Data.SqlClient, untriaged
Milestone:	-

[ghost]

Tagging subscribers to this area: @dotnet/area-system-globalization
See info in area-owners.md if you want to be subscribed.

Issue Details

---

Description

The String comparison logic returns incorrect result for some string.

Reproduction Steps

using System;
using System.Globalization;

public class Program
{
   public static void Main()
   {
       Console.WriteLine(new CultureInfo("en-US").CompareInfo.Compare("ʻ", "", CompareOptions.IgnoreNonSpace));
   }
}

Expected behavior

Console prints 0

Actual behavior

Console prints 1

Regression?

It's a regression.
It works fine in .NET framework 4.7.2 so it appears the bug is limited to .NET core

Known Workarounds

None that I'm aware of.

Configuration

.NET 8 Windows x64

Other information

This seems to be a regression. It works in .NET framework but not .NET core

Author:	clement911
Assignees:	-
Labels:	area-System.Globalization, untriaged
Milestone:	-

[huoyaoyuan]

There is wide globalization change between .NET Framework and .NET Core. .NET Framework uses Windows NLS while .NET Core uses ICU by default. See https://learn.microsoft.com/dotnet/core/extensions/globalization-icu .

With that said, this may be a bug of CompareOptions.IgnoreNonSpace handling in .NET Core.

[clement911]

@huoyaoyuan the doc says that ICU is used from .NET 5 onwards but I can reproduce the issue even with .NET Core 3.1 so it might not be related to the ICU change

[clement911]

Actually sorry, I cannot reproduce with .NET Core 3.1
We came across this bug because it makes SqlString comparison not consistent with sql server's behavior.

[tarekgh]

Closing this as per replies. Apps want to get the old behavior can use use nls instead of icu. We don't recommend it though as in the future this will be legacy obsolete behavior.