Bug in .NET 6.0 which does not occur in .NET 5.0 when saving and loading png

[synercoder]

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

Description

I use a library to render PDF pages to image data. This data is in BGRA format. I then use Image.LoadPixelData<Bgra32>(bytes, width, height) to load the data, and then use the data.

In my unit test for this library I load the Bgra32 data after rendering, then save as PNG. Later on I open that file/stream again using Image.Load. It then throws an exception: SixLabors.ImageSharp.ImageFormatException : Bad method for ZLIB header: cmf=32.

Steps to Reproduce

I have saved the raw bgra data into a file, and made a minimal bug sample. The test run on GitHub actions can be found here: https://github.com/synercoder/ImageSharpNet6Bug/runs/3675201091?check_suite_focus=true

As can the minimal sample test: https://github.com/synercoder/ImageSharpNet6Bug/blob/main/ImageSharpBugTests/BugTests.cs

System Configuration

• ImageSharp version: 1.0.3
• Environment (Operating system, version and so on): Windows 10, bug also reproduced in GitHub Actions on Windows-latest
• .NET Framework version: My pc & Github actions: 6.0.100-rc.1.21458.32
• Additional information: Works in .NET 5.0 & images used in the raw file are from Pexels.com under the royalty-free license if that was any worry.

[antonfirsov]

This is most likely duplicate of #1704, which got fixed by #1707.

Can you please check if it works with the nighlties?

[synercoder]

Will do...

[synercoder]

My searching(/understanding) of the issues was not enough apparently, also works currently on my pc & github actions. So I guess close me as duplicate.

[synercoder]

@antonfirsov could my test case / image be a good addition to the imagesharp test suit (as a regression test mayhaps)? If so I could create/shape a PR this evening/tomorrow.

[antonfirsov]

Yeah #1707 went in without a test, a test case would be an addition we appreciate!