Wow, I haven’t need to think about resource forks in a very long time.
I’m not certain that APFS in fact supports resource forks? I kinda think it stuffs them in the age-old AppleDouble format? Things like the Finder tag colors use resource forks, but very little else.
What in .webloc files is stuffed in a resource fork?
Hm, I’m going to have to do a little more reading on AppleDouble format.
For .webloc files, I’m using xattr to hide the file extension with com.apple.FinderInfo and then set the file icon with NSWorkspace.shared.setIcon(). Both of these appear to modify the resource fork on disk and then I use relevance to verify the webloc URL dictionary is set and something like length of resource fork of it > 1000 to determine if the Finder properties were set successfully.
The result is a clean looking .webloc file that can be put on the Desktop, Dock or in the Applications folder.
In any case, the behavior seems to have changed recently and I don’t know enough about what the inspector is doing to suggest how to fix it and the resulting length/size seems inconsistent with xattr or ..namedfork/rsrc.