Inpaint brush does not respect pixel selection

[NotMyFault]

When you use the inpaint brush with „current layer & below“ while having a very small selection of e.g. 2x2px and a default brush of 64x64px, the brush kind of ignores the selection: while only the selected pixels get inpaint, the brush never the less copies the content of the source layer into the target layer ignoring the selection.

in theory it create the same visual result, but it will overwrite formerly transparent areas of the target layer with a copy of the source layer - at least totally unexpected and a bug in my view.

steps to reproduce

1. create new document
2. add pixel layer 
3. fill in blue
4. select any 2x2 px
5. paint over in red
6. add pixel layer
7. choose inpaint brush, set size to 64 (was default in my case)
8. set mode to current and below
9. inpaint selected area by generously painting (remember, the selection schools limit the area)
10. deactivate bottom layer to inspect top layer

Expected: only selected area is overwritten / inpainted

observed: a large area is inpainted.

This behavior becomes a real issue in case you have another layer between both, where you have content partially covering the selected area. If you deactivate this layer while inpainting, the top layer overwrites the area outside the selection with bottom layer content. So after finishing inpainting and reactivating the middle layer, its content became covered by the unwanted copy from the bottom layer.

[Lee D]

@NotMyFault Thank you for the report, I've confirmed and logged it with the developers.