Unexpected ArgumentOutOfRangeException at SixLabors.ImageSharp.Image.InternalDetectFormat(Configuration, Stream)

[Poker-sang]

Prerequisites

• I have written a descriptive issue title
• I have verified that I am running the latest version of ImageSharp
• I have verified if the problem exist in both DEBUG and RELEASE mode
• I have searched open and closed issues to ensure it has not already been reported

ImageSharp version

3.1.1

Other ImageSharp packages and versions

No

Environment (Operating system, version and so on)

Windows 11 (22631.2861)

.NET Framework version

8.0

Description

at System.ThrowHelper.ThrowArgumentOutOfRangeException(ExceptionArgument argument, ExceptionResource resource)
at System.IO.BufferedStream.set_Position(Int64 value)
at SixLabors.ImageSharp.Image.InternalDetectFormat(Configuration configuration, Stream stream)
at SixLabors.ImageSharp.Image.DiscoverDecoder(DecoderOptions options, Stream stream)
at SixLabors.ImageSharp.Image.DecodeAsync[TPixel](DecoderOptions options, Stream stream, CancellationToken cancellationToken)
at SixLabors.ImageSharp.Image.<>c__DisplayClass86_0`1.b__0(Stream s, CancellationToken ct)
at SixLabors.ImageSharp.Image.d__88`1.MoveNext()
at Pixeval.Util.IO.IoHelper.d__39.MoveNext() at C:\WorkSpace\Pixeval\src\Pixeval\Util\IO\IOHelper.Imaging.cs: Line 187

Steps to Reproduce

imageStream is Windows.Storage.Streams.IRandomAccessStream

The Exception is not always thrown.

try
{
    var a = imageStream.Position; // a = 1700
    var b = imageStream.Size; // b = 1700
    var h = imageStream.CanRead; // h = true
    var i = imageStream.CanWrite; // i = false
    imageStream.Seek(0);
    var c = imageStream.Position; // c = 0
    var d = imageStream.Size; // d = 1700
    using var image = await Image.LoadAsync<Bgra32>(imageStream.AsStreamForRead()); // Exception thrown
    var softwareBitmap = new SoftwareBitmap(BitmapPixelFormat.Bgra8, image.Width, image.Height, BitmapAlphaMode.Premultiplied);
    var buffer = new byte[4 * image.Width * image.Height];
    image.CopyPixelDataTo(buffer);
    softwareBitmap.CopyFromBuffer(buffer.AsBuffer());
    return softwareBitmap;
}
catch (Exception e) // Non-negative number required. (Parameter 'value')
{
    Debugger.Break();
    Console.WriteLine(e);
    throw;
}

Images

No response

[JimBobSquarePants]

There isn’t enough here to reproduce a potential issue I’m afraid. We’d need a reduced sample running within an application with an image known to trigger the exception.

[Poker-sang]

I am sorry but this issue does not always happen. I am trying to find a way to reproduce the problem consistently.

[Poker-sang]

Looks like AsStreamForRead() accidentally makes Stream.Position negative sometimes. It's not a bug from ImageSharp actually. Should we check Stream.Position positive in Image.Load to avoid this, and better help users locate bugs?

[JimBobSquarePants]

In the years I’ve been developing the library, I’ve never seen a negative stream position before.

[Poker-sang]

Me neither. However it actually happened in my screenshot.