v0.3.0's listen wrapper treated every listen beyond the first at a
given sockaddr as a skip-core "duplicate", which was correct for
two `listen 80 device=X/Y;` lines in one server block but broke on
the real deployment pattern where every server-*.conf pulls in the
same `include listens.conf;`. Symptoms:
* every server block after the first ended up with no listen
directive processed, so nginx assigned them the default
`*:80`, producing a flood of "conflicting server name"
warnings and attaching every server block to an unrelated
wildcard bind;
* the bindings list grew linearly with the number of server
blocks, so init_module tried to create (server_blocks) ×
(devices × families) listening sockets and hit EMFILE.
Replace the single dedup with two independent checks:
* listens_seen is a (cscf, sockaddr) ledger. The core listen
handler is invoked at most once per (server block, sockaddr),
matching nginx's own duplicate check so server-block N just
attaches its cscf to the existing address via
ngx_http_add_server.
* `bind` is added only for the first global occurrence of each
sockaddr; subsequent cscfs inherit opt.set/opt.bind from the
first, which is what keeps nginx's "duplicate listen options"
check happy across server blocks.
* bindings dedup on (sockaddr, device) globally, so init_module
creates one socket per unique pair regardless of how many
server blocks reference it.
Add a regression test at tests/01-module/ that wires three server
blocks to the same ipng-listens.inc and asserts that nginx -t is
clean and exactly four sockets are bound on port 8080.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Pim van Pelt
1f144f4c19