Merging child layers copies info from parent layer

[AdamF]

Affinity Photo 2.1.1 (Latest version as of July 11 2023)
MacBook Pro 15-inch, 2019
macOS 13.4.1 (22F82)

Repro steps:
* File > New > Web XGA
* Create a new pixel layer and name it “Parent”
* Paint a shape with a basic round brush in black on the Parent layer
* Create two new pixel layers and make them children of the Parent layer
* Paint a red shape in one of the child layers (leave some black pixels from the parent visible)
* Paint a blue shape in the other child layer (leave some black pixels from the parent visible)
* Select the two child layers in the layer studio
* Layer > Merge Selected
* Drag the single merged child layer out of the Parent
* Delete the Parent layer

Expected result: The merged child layer should not contain any black pixels. The areas that were not painted with blue or red shapes should remain transparent when merging.

Actual result: The merged child layer contains black pixels

Notes
* Uploaded file contains history
* Also reproduces if I use “Layer > Merge Down” to merge the two child layers
* Reproduces with hardware acceleration on and off (tried both)
* Merging works correctly if the two layers are not child layers
* Also reproduces on iPad (version 2.1.1.1847)
* This has been a problem in Affinity Photo 2 for both mac and iPad for as long as I can remember
 

ParentRepro.afphoto

[Old Bruce]

Unsure of what you are actually needing from the nesting. Are you wanting the black layer to clip the red and blue layers? I enlarged them here in this screenshot.

[AdamF]

Yes, I want the black layer to clip the blue and red layers. I know this can also be done with masking, but I find child layers very convenient, e.g. if I've already painted a tree and then I want to experiment with new highlights and shadows without changing the silhouette.

[NathanC]

Welcome to the forums @AdamF,

I've replicated and logged this with the developers, many thanks!