String corruption with VipsForeignLoad / VipsForeignSave when using in Unity

When trying to use NetVips in Unity (2020.3.12f1), we are seeing string corruption issues with methods that call VipsForeignLoad / VipsForeignSave:

For example:

public Image GetImage()
{
   return Image.NewFromFile("/Users/jmillard/Desktop/test.png");
}

errors with:

VipsException: unable to load from file /Users/jmillard/Desktop/test.png
VipsForeignLoad: file "/Users/jmillard/Desktop/test.png�Le�" does not exist

and

var path = texture.GetUnityFilename(folder);
Debug.Log($"Writing to {path}");
var im = texture.GetImage();
File.WriteAllBytes(path, im.WriteToBuffer(".png"));

errors with:

VipsException: unable to write to buffer
VipsForeignSave: ".pngallrolling3" is not a known buffer format

We are seeing this on MacOS and Windows. (Did not try on Linux yet)

[kleisauke]

NetVips v2.0.1 is now available. Thanks for reporting this!

[kleisauke]

Thanks for these instructions, I could reproduce it on Windows. It seems that the Mono version provided by Unity doesn’t properly null-terminate strings(?), I was able to fix/workaround this with commit https://github.com/kleisauke/net-vips/commit/95a9627d7d48c6fa1ab97f80748e54aa38710eab (which should be available as nightly version 2.0.0 build number 277).

I’ll investigate further why this only occurs on Mono and not on .NET Core/Framework, in the meantime you might also be interested in these changes: https://github.com/freezy/VisualPinball.Engine/compare/refactor/scene-netvips-test...kleisauke:refactor/scene-netvips-test