Loading image with DecoderOptions { MaxFrames = 1 } loads multiple frames for attached png file

[danbystrom]

Prerequisites

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

ImageSharp version

3.1.4

Other ImageSharp packages and versions

-

Environment (Operating system, version and so on)

Windows 11

.NET Framework version

net7.0

Description

Loading an image with the following statement: using var img = await SixLabors.ImageSharp.Image.LoadAsync(new DecoderOptions { MaxFrames = 1 }, fileStream); should just load one frame, which is does for all images I have tested on, EXCEPT the attached one, where it imports all 42 frames.

Steps to Reproduce

Load the attached "duck.png" like this:

  using var fileStream = File.OpenRead(@"c:\temp\duck.png");
  using var img = await SixLabors.ImageSharp.Image.LoadAsync(new DecoderOptions { MaxFrames = 1 }, fileStream);
  Assert.AreEqual(1, img.Frames.Count);

Images