IImageViewHandler + Task.Delay, can cause infinite image loading on Android

[jonathanpeppers]

Description

Steps to Reproduce

1. Create a new Xamarin.Forms project Flyout template
2. Add an IImageViewHandler
3. When the app runs, you can see Xamarin.Forms load images continuously in a loop.

[assembly: ExportImageSourceHandler(typeof(FileImageSource), typeof(Android.Glide.ImageViewHandler))]
//...
public class ImageViewHandler : IImageViewHandler
{
	public async Task LoadImageAsync(ImageSource source, ImageView imageView, CancellationToken token = default)
	{
		Log.Debug("IVH", "IImageViewHandler of type `{0}`, `{1}` called.", GetType(), nameof(LoadImageAsync));
		if (source is FileImageSource file)
		{
			var drawable = ResourceManager.GetDrawableByName(file.File);
			if (drawable != 0)
			{
				Log.Debug("IVH", "Loading `{0}` as an Android resource", file.File);

				// Comment this line to fix it
				await Task.Delay(10);

				imageView.SetImageResource(drawable);
			}
		}
	}
}

I found this from a bug report of a developer using glidex.forms:

jonathanpeppers/glidex#87

Expected Behavior

The images load once.

Actual Behavior

The images appears to load over and over indefinitely.

Basic Information

• Version with issue: 4.8.0.1451 and 5.0.0.1558-pre3
• Last known good version: 4.5.0.356 definitely worked, no idea which version broke.
• Platform Target Frameworks:
  • Android: 30 or 28
• Android Support Library / AndroidX Version:
• Affected Devices: all

Device Logs

The attached sample logs this over and over:

[IVH] Loading `icon_about.png` as an Android resource
[IVH] IImageViewHandler of type `Android.Glide.ImageViewHandler`, instance created.
[IVH] IImageViewHandler of type `Android.Glide.ImageViewHandler`, `LoadImageAsync` called.
[IVH] Loading `icon_about.png` as an Android resource
[IVH] IImageViewHandler of type `Android.Glide.ImageViewHandler`, instance created.
[IVH] IImageViewHandler of type `Android.Glide.ImageViewHandler`, `LoadImageAsync` called.
[IVH] Loading `icon_about.png` as an Android resource
[IVH] IImageViewHandler of type `Android.Glide.ImageViewHandler`, instance created.
[IVH] IImageViewHandler of type `Android.Glide.ImageViewHandler`, `LoadImageAsync` called.
[IVH] Loading `icon_feed.png` as an Android resource
[IVH] IImageViewHandler of type `Android.Glide.ImageViewHandler`, instance created.
[IVH] IImageViewHandler of type `Android.Glide.ImageViewHandler`, `LoadImageAsync` called.
[IVH] Loading `icon_feed.png` as an Android resource
[IVH] IImageViewHandler of type `Android.Glide.ImageViewHandler`, instance created.
[IVH] IImageViewHandler of type `Android.Glide.ImageViewHandler`, `LoadImageAsync` called.
[IVH] Loading `icon_feed.png` as an Android resource
[IVH] IImageViewHandler of type `Android.Glide.ImageViewHandler`, instance created.
[IVH] IImageViewHandler of type `Android.Glide.ImageViewHandler`, `LoadImageAsync` called.
[IVH] Loading `icon_feed.png` as an Android resource

Reproduction Link

Note you might need to change the Task.Delay(1) to a higher number to see the problem more frequently:

App96.zip

Workaround

Only workaround is to not use glidex.forms, or comment out the Task.Delay(1) in my example.