Fix testDownsamplingWithEdgeCaseSize fail

[kittisak-phetrungnapha]

In Xcode 15.3 and Swift 5.10, below code does not return nil if kCGImageSourceThumbnailMaxPixelSize is 0. It returns some image size 64*64 . I am not sure why and it does not make any sense. Maybe a bug from Apple?

let downsampleOptions: [CFString : Any] = [
            kCGImageSourceCreateThumbnailFromImageAlways: true,
            kCGImageSourceShouldCacheImmediately: true,
            kCGImageSourceCreateThumbnailWithTransform: true,
            kCGImageSourceThumbnailMaxPixelSize: 0 // even we set it to 0
        ]

public func CGImageSourceCreateThumbnailAtIndex(_ isrc: CGImageSource, _ index: Int, _ options: CFDictionary?) -> CGImage?

Before fixing:

I just fix the test fail by assert with image size 64*64 and it's passed.

[onevcat]

Thanks for it and I appreciate the effort you made for it.

I am preparing a major update currently and it has been also fixed here in the v8 branch:

d7505c6

As this PR seems to be duplicated to that fix and might fail the test if built with an earlier Xcode (which usually happens on CI), so maybe we can close this one without merging.

However, it is indeed a good idea to have this fix for the master branch as well. If you'd like, can you try to cherry pick that commit above and send another one to the master? Then we can merge it without worrying any further conflicting.

[kittisak-phetrungnapha]

@onevcat done.