Unchecking preview checkbox (for filter) when editing multi-layered images restores picture partially or does not restore at all

[VladimirMarkelov]

Thank you for the fast and nice editor!

Recently I ran into a small trouble with filters. I was not able to reproduce it with a single-layered images, though I am not sure if they are free from this issue. For the example video I was able to reproduce when I was applying a filter. Steps:

• Create a new image with two layers
• Choose the bottom one (it is easier to reproduce if you try applying a filter to non-top layer as I did in my video)
• Open a filter and try modify the layer. Preview works fine and everything works great
• Now uncheck the "preview" checkbox

I experienced three different results:

1. Everything works - for a top layer it is the most likely result
2. Checking/unchecking "preview" does nothing - in both states the image is displayed in modified state. Only clicking "cancel" button restores the original image look
3. Unchecking "preview" restores only part of an image (I took a video of it, see in the attachment).

The surprising part is that the checkbox correctly affects the thumbnail of the image (in my video you can see in the right bottom corner), only editing area is glitching.

image-preview-glitch.mp4