fix: port remaining applicable upstream fixes (timer guards, dead pool path)

[ronag]

Audit of nodejs/undici since the fork point (a180465f, v7.5.0 — 842 upstream commits, 125 touching files this fork still ships) for anything applicable but missing here. Nearly everything relevant is already in — often via this fork's own commits, sometimes ahead of upstream. Two real gaps came out of it.

fix(timers) — handles without refresh() / unref()

refreshTimeout() assumed every handle from the ambient setTimeout is a native Node Timeout. A shimmed setTimeout that returns a bare id makes both paths throw:

• creation → fastNowTimeout.unref is not a function
• reschedule → fastNowTimeout.refresh is not a function

Either one kills the FastTimer tick loop for the rest of the process, so every headers/body/keep-alive timeout silently stops firing. This fork explicitly supports mocked environments (client-h1.js branches on JEST_WORKER_ID), so it is reachable. Ports nodejs#4213, plus a clearTimeout of the old handle before replacing it so a shim without refresh() can't leave a duplicate tick running.

Regression test added to test/timer-handles.js; it fails on master with TypeError: fastNowTimeout.unref is not a function.

fix(pool) — remove the unreachable kRemoveClient

kRemoveClient has had no callers since kDetachClient took over stale-client removal. It still carried two upstream bugs fixed after the fork point:

• pre-nodejs/undici#5151 needDrain inversion — it set needDrain when a client was available
• pre-nodejs/undici#5145 deferred splice (removal only landing in the close() callback)

Rather than port fixes into a method nothing calls, removed it and its symbol/export. Alternative, if you'd rather keep the surface: negate the some() and splice synchronously to match upstream.

Checked and deliberately not ported

Upstream	Why not
nodejs#5620 setEncoding() body truncation	Already fixed here by da650fc4 via kPreservedBuffer + the push() override. Upstream reworked it to re-encode state.buffer instead; behaviourally equivalent, and swapping it out is a hot-path refactor with no behaviour gain.
nodejs#5606 / nodejs#5499 / nodejs#5397 idle socket validation	Deliberate divergence — this fork keeps a referenced setImmediate (f4724ec9), which is our still-open nodejs#5609. Upstream reverted to an unref'd setTimeout(0).
nodejs#5577 DNS origin hostname on sockets	Needs the DNS interceptor, which this fork doesn't ship. The client[kServerName] half is already covered by the https: servername-change branch in _resume.
nodejs#5547 / nodejs#4831 IP prioritization hints, nodejs#4175 + nodejs#4807 clientTtl, nodejs#4365 maxOrigins, nodejs#4296 pingInterval	Features this fork doesn't carry.
nodejs#5231 writeBlob assert, nodejs#5120 Content-Range, nodejs#4311 maxRedirections, nodejs#4289 body diagnostics channels, all h2/websocket/proxy/cache/fetch work	Code paths removed from this fork.
nodejs#5273, nodejs#5356, nodejs#5375, nodejs#5389, nodejs#5060, nodejs#5062, nodejs#5007, nodejs#4923, nodejs#4937, nodejs#4775, nodejs#4758, nodejs#4931 CRLF/dup-header validation, 89323ff pipelined response errors, nodejs#5151 in dispatch(), nodejs#5125 parser WeakRef, nodejs#5459 QUERY	Verified already present.

Verification

• borp --expose-gc -p "test/*.js" — 570 pass, 0 fail, 6 skip
• borp -p "test/node-test/**/*.js" — 151 pass, 0 fail
• tsc -p test/types/tsconfig.json — clean
• eslint --no-cache . — clean

All validation ran locally on Node.js 26.5.0.

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[claude]

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[Copilot]

Pull request overview

Ports two remaining upstream fixes into this fork: (1) makes the FastTimer tick-loop resilient to environments where setTimeout returns non-Node timer handles, and (2) removes an unused/stale PoolBase client-removal path.

Changes:

• Harden refreshTimeout() against timer handles without refresh() / unref(), and clear the previous tick handle before replacing it.
• Add a regression test covering “bare id” timer handles to ensure only one tick is scheduled.
• Remove the dead kRemoveClient symbol/method/export from PoolBase.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.

File	Description
test/timer-handles.js	Adds coverage for mocked timer handles that don’t implement Node’s timer lifecycle methods.
lib/util/timers.js	Makes FastTimer’s backing tick scheduling tolerate missing refresh()/unref() and avoids duplicate ticks.
lib/dispatcher/pool-base.js	Drops the unused kRemoveClient path and its export to reduce dead/buggy surface.

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[Copilot]

Pull request overview

Copilot reviewed 3 out of 3 changed files in this pull request and generated no new comments.