/usr/share/nftables.d/chain-post will not get included if corresponding chain is not used in /etc/config/firewall

I'm building a (hopefully) reusable package to add support to firewall expectations using conntrackd -- helpers essentially. I notice that when I am placing a chain in a directory that matches a "standard" table (e.g srcnat_zone), and if the zone doesn't itself have any rules, the included rules do not get rendered.

This is despite the misleading message that Automatically including '/usr/share/nftables.d/chain-post/srcnat_zone/X.nft is printed when running /etc/init.d/firewall reload.

I dug into the code and it seems like the chains are rendered only if there's a corresponding set of rules in /etc/config/firewall. Should fw4 also emit the chain if an include requests to insert rules into a chain? I'll be happy to work on a patch if this is desirable.

I've been able to workaround this by using the table-post hook instead -- but I would imagine more granular includes would be advantageous.

Start with the /usr/share/nftables.d/chain-post/ include path and /etc/init.d/firewall reload, then trace the fw4 code that decides whether a standard chain is rendered. Reproduce the srcnat_zone case with no matching rules in /etc/config/firewall; done means the requested chain-post include is rendered rather than only reported as automatically included.