Exception SixLabors.ImageSharp.ImageFormatException: 'reserved bytes should be zero' when using Image.LoadAsync about imagesharp

[gieniowski]

@JimBobSquarePants I did the update to the v3.1.4 and I experience the same behavior. Could you reopen the issue please?

[hey-red]

Same issue with v3.1.4.
But I had same behavior both on debug and release mode.

file.zip

[JimBobSquarePants]

@hey-red was that file encoded using v3.1.4?

@gieniowski I cannot replicate your issue with the image and code provided with v3.1.4.

WebP files encoded using >= 3.1.0 and < v3.1.4 versions will still trigger an error because the encoder wrote over the reserved bytes.

[hey-red]

@JimBobSquarePants Oh, sorry, no. I think this file was taken somewhere from web.
I got same exception "'reserved bytes should be zero'" while loading
using Image image = Image.Load(@"C:\file.webp");

However in browsers/paint.net I can view file without any issues.

[JimBobSquarePants]

I could get rid of the exception; it is a violation of the specification but harmless enough.

[hey-red]

@JimBobSquarePants I'm not sure if this is the correct line, but it seems that libwebp is simply skip these reserved bytes without error.
https://github.com/webmproject/libwebp/blob/main/src/demux/demux.c#L556

[JimBobSquarePants]

Yeah. That's the animated decoder (don't ask why they split everything out). They do the same in the standard one by reading the uint instead of each byte.

https://github.com/webmproject/libwebp/blob/3cada4cef46e1ad2ba47a801ac453af95936dfdb/src/dec/webp_dec.c#L124

I don't know when I'll get round to it personally but if someone wants to PR against the release/v3.1.x branch I'll accept it.