When using the "create from clipboard" functionality if the background type in the "Content" tab is set to "As fill layer" the clipboard image is inserted as an alpha mask to the background layer. I would have expected that when using this feature the clipboard image would be inserted on a raster layer above the background layer. I don't think the current behaviour is expected or useful, the resultant image does not resemble what was in the clipboard. The reason this is a problem is that I always use the fill layer background type when creating normal documents, and this preference is also applied when creating from clipboard. To work around this issue I would have to manually change the background type every time. I suggest that either a) the preferences for "custom document" and "create from clipboard" are split from each other so I can have one background type for one and one for the other, or b) the background type is ignored and a raster layer is always used or c) whenever "fill layer" is selected a new raster layer with the image is always inserted above the background. STEPS TO REPRODUCE 1. Go to File > New > Create from Clipboard 2. In the content tab set the background to "As fill layer" 3. Set layers to 2 4. Click create OBSERVED RESULT A fill background with the image as an alpha channel is created. The raster layer above is completely empty. The document does not resemble the clipboard image. EXPECTED RESULT A fill background layer is created with a raster layer containing the image above it.
Every one of those three options creates an empty raster layer above the background layer and the content of the background layer is determined by the colour/transparency settings and the clipboard contents. As such, the Fill layer option seems to be behaving normally and predictably from a purely logical viewpoint. I can think of situations when someone might want a background layer to be a Fill layer with semi-opaque or transparent regions. If they can't have that using Create from Clipboard then there are workarounds as there are workarounds for you. I'd suggest that this is more of a wishlist item than a bug.
Sure, the behaviour is consistent from an entirely logical perspective but I don't think the current behaviour is consistent at all with what the user would expect to happen. As I see it the "create from clipboard" function is meant to be a quick and easy way to get an image into the program exactly as it appears in their clipboard. I can't imagine a single person using this feature is expecting their image to become an alpha mask for a solid colour layer. What is the purpose in frustrating users by replacing what could be a useful feature with an all but completely useless one just to remain "logically consistent"? Although, if it is desired that all layer options behave in the exact same way then how about this? For 1 layer, the behaviour is as it currently is. For >=2 layers the fill layer is created as specified but then the image is inserted on raster layer 2. When >2 all other empty layers are then inserted above. I think the above solution would remain logically consistent while still making the feature useful when using the fill layer type. When I found this "bug" my above suggestion was what I actually tried to do afterwards in the hope that it might work that way, but alas it currently does not.
It will be a question of how many users (and developers) think it will be a useful and valuable change to make. All you can do now is wait for more comments and developer decisions, which may take some time.
It is consistent with options you choose: you want one layer, then the content is going to be put on the first layer; you selected the option with Fill layer, so the content is going to be put on the Fill layer (because you want only one); so the content is changed into alpha, since that's the only thing that would make sense. The current behaviour is consistent, so changing it is a wish and requires discussion with other artists.