On windows image download fails randomly

[nirdil]

Image downloads randomly fail (tested on Wikipedia) with a forbidden User-Agent policy error. Retrying the download doesn't resolve it. Restarting the app sometimes resolve it.

I've written a test app showcasing how it randomly fails on different images - https://github.com/nirbil/FFImageTester It's configured to use only memory cache and it iterates through some random images from Wikipedia. Notice how it fails on different images, and after restarting the app it may fail on others.

I tried to set a custom HttpClient that adds the user-agent string through the ImageService initialization API, that but that had no effect. I also tried downgrading to version 2.4.9.961 like was suggested on some other similar bugs but that had no effect. Eventually I managed to bypass the bug by using that HttpClient to get the stream on my own and set a StreamImageSource. The downside of that however is that you lose caching for those resources.

Running under UWP and latest FFImageLoading 2.4.11.982.

[nirdil]

Eventually I managed to circumvent this by registering to the error event and in case of a failure attach a custom DataResolver that fetches the right stream with an user-agent enabled HttpClient and then call ReloadImage