Runtime: System.Drawing.Font.ToLogFont runtime error on Ubuntu 18.04 LTS

[hwfbcisod]

Description

The System.Drawing.Font.ToLogFont method seems to work well in a Windows environment. Using it in a Linux environment produces runtime errors. I've prepared a sample console application which illustrates the issue.

Exceptions

Unhandled exception. System.ArgumentException: Value does not fall within the expected range. (Parameter 'logFont')
   at System.Drawing.Font.ToLogFont(Object logFont, Graphics graphics)
   at System.Drawing.Font.ToLogFont(Object logFont)
   at TestFonts.Program.Main(String[] args) in /home/hwfbcisod/Desktop/TestFontsNew/Program.cs:line 27

Source Code

```C#
using System;
using System.Drawing;
using System.Runtime.InteropServices;

namespace TestFonts
{
class Program
{
static void Main()
{
var font = new Font(new FontFamily("Arial"), 20, FontStyle.Bold);
var logFont = new LOGFONT();
font.ToLogFont(logFont);
Console.WriteLine(logFont.lfHeight);
}

    [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]
    private class LOGFONT
    {
        public int lfHeight;
        public int lfWidth;
        public int lfEscapement;
        public int lfOrientation;
        public int lfWeight;
        public byte lfItalic;
        public byte lfUnderline;
        public byte lfStrikeOut;
        public byte lfCharSet;
        public byte lfOutPrecision;
        public byte lfClipPrecision;
        public byte lfQuality;
        public byte lfPitchAndFamily;
        [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 32)]
        public string lfFaceName;
    }

}

}

### NuGet Packages

[System.Drawing.Common](https://www.nuget.org/packages/System.Drawing.Common/)

## Configuration

### .NET Info

.NET SDK (reflecting any global.json):V
Version: 5.0.100
Commit: 5044b93829

Runtime Environment:
OS Name: ubuntu
OS Version: 18.04
OS Platform: Linux
RID: ubuntu.18.04-x64
Base Path: /usr/share/dotnet/sdk/5.0.100/

Host (useful for support):
Version: 5.0.0
Commit: cf258a14b7

.NET SDKs installed:
5.0.100 [/usr/share/dotnet/sdk]

.NET runtimes installed:
Microsoft.AspNetCore.App 5.0.0 [/usr/share/dotnet/shared/Microsoft.AspNetCore.App]
Microsoft.NETCore.App 5.0.0 [/usr/share/dotnet/shared/Microsoft.NETCore.App]

### OS Info

Distributor ID: Ubuntu
Description: Ubuntu 18.04.3 LTS
Release: 18.04
Codename: bionic
```

Note: The Ubuntu distribution is running in a VM. Reproduced on both a local Hyper-V instance and on an Azure VM.

Regression?

The above problems occur both in .NET Core 3.1 and .NET Core 5. I haven't tested with other versions.

[msftbot[bot]]

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Issue Details

Description:	Description The System.Drawing.Font.ToLogFont method seems to work well in a Windows environment. Using it in a Linux environment produces runtime errors. I've prepared a sample console application which illustrates the issue. Exceptions Unhandled exception. System.ArgumentException: Value does not fall within the expected range. (Parameter 'logFont') at System.Drawing.Font.ToLogFont(Object logFont, Graphics graphics) at System.Drawing.Font.ToLogFont(Object logFont) at TestFonts.Program.Main(String[] args) in /home/hwfbcisod/Desktop/TestFontsNew/Program.cs:line 27 Source Code ```C# using System; using System.Drawing; using System.Runtime.InteropServices; namespace TestFonts { class Program { static void Main() { var font = new Font(new FontFamily("Arial"), 20, FontStyle.Bold); var logFont = new LOGFONT(); font.ToLogFont(logFont); Console.WriteLine(logFont.lfHeight); } [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)] private class LOGFONT { public int lfHeight; public int lfWidth; public int lfEscapement; public int lfOrientation; public int lfWeight; public byte lfItalic; public byte lfUnderline; public byte lfStrikeOut; public byte lfCharSet; public byte lfOutPrecision; public byte lfClipPrecision; public byte lfQuality; public byte lfPitchAndFamily; [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 32)] public string lfFaceName; } } } ### NuGet Packages [System.Drawing.Common](https://www.nuget.org/packages/System.Drawing.Common/) ## Configuration ### .NET Info .NET SDK (reflecting any global.json):V Version: 5.0.100 Commit: 5044b93829 Runtime Environment: OS Name: ubuntu OS Version: 18.04 OS Platform: Linux RID: ubuntu.18.04-x64 Base Path: /usr/share/dotnet/sdk/5.0.100/ Host (useful for support): Version: 5.0.0 Commit: cf258a14b7 .NET SDKs installed: 5.0.100 [/usr/share/dotnet/sdk] .NET runtimes installed: Microsoft.AspNetCore.App 5.0.0 [/usr/share/dotnet/shared/Microsoft.AspNetCore.App] Microsoft.NETCore.App 5.0.0 [/usr/share/dotnet/shared/Microsoft.NETCore.App] ``` OS Info Distributor ID: Ubuntu Description: Ubuntu 18.04.3 LTS Release: 18.04 Codename: bionic Note: The Ubuntu distribution is running in a VM. Reproduced on both a local Hyper-V instance and on an Azure VM. Regression? The above problems occur both in .NET Core 3.1 and .NET Core 5. I have't tested with other versions.
Author:	hwfbcisod
Assignees:	-
Labels:	area-System.Drawing, untriaged
Milestone:	-

[am11]

The size check is failing because size of LOGFONT type is different than the one defined by runtime: https://github.com/dotnet/runtime/blob/6cb16e12fd912c28f2ab4577414b4a2d8b321a28/src/libraries/Common/src/Interop/Windows/User32/Interop.LOGFONT.cs#L12

-       [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]
-       private class LOGFONT
+       [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
+       private unsafe struct LOGFONT
        {
            public int lfHeight;
            public int lfWidth;
            public int lfEscapement;
            public int lfOrientation;
            public int lfWeight;
            public byte lfItalic;
            public byte lfUnderline;
            public byte lfStrikeOut;
            public byte lfCharSet;
            public byte lfOutPrecision;
            public byte lfClipPrecision;
            public byte lfQuality;
            public byte lfPitchAndFamily;
-           [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 32)]
-           public string lfFaceName;
+           private fixed char _lfFaceName[32];
+           public string lfFaceName
+           {
+               get { fixed (char* c = _lfFaceName) { return new string(c); } }
+           }
+       }

build as dotnet build -p:AllowUnsafeBlocks=True and finally dotnet run.

[safern]

Thanks, @am11 that seems accurate.

@hwfbcisod please confirm if that fixes your issue 😄

[hwfbcisod]

Thank you, @am11.

@safern Yes, that seems to work. At least it does on my Hyper-V VM.

[safern]

Great. Thanks for confirming @hwfbcisod. Please let us know if we can help further. I'm closing the issue based on the conversation above.

[TrayanZapryanov]

@am11 Do you have an idea why example described in issue works on Windows and fails in Linux ?
If you search over internet one of the first sites describing LOGFONT is pinvoke.net and it gives you wrong signature.
Maybe we need a better documentation for this .

[am11]

@TrayanZapryanov, the official docs of ToLogFont https://docs.microsoft.com/en-us/dotnet/api/system.drawing.font.tologfont?view=dotnet-plat-ext-5.0 points to this definition of win32 struct https://docs.microsoft.com/en-us/windows/win32/api/wingdi/ns-wingdi-logfonta.

In the pinvoke.net documentation you mentioned, we only need to change CharSet.Auto to CharSet.Unicode, because CharSet.Auto on Unix-y system is UTF8 in .NET and Unicode on Windows: https://docs.microsoft.com/en-us/dotnet/standard/native-interop/charset. (always better to explicitly specify the encoding, rather than relying on default behavior in such cases).