From a957213e7d09306e94603f00a93c90bb681eed09 Mon Sep 17 00:00:00 2001
From: marcus-pousette-hp <marcus-pousette-hp@users.noreply.github.com>
Date: Mon, 18 May 2026 22:39:06 +0200
Subject: [PATCH] Skip idle close peer update scans

---
 lib/replicator.js | 28 ++++++++++++++++++++++++---
 test/replicate.js | 49 +++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 74 insertions(+), 3 deletions(-)

diff --git a/lib/replicator.js b/lib/replicator.js
index 369a6f08..18d408ed 100644
--- a/lib/replicator.js
+++ b/lib/replicator.js
@@ -754,7 +754,7 @@ class Peer {
 
     if (this.remoteOpened === false) {
       this.replicator._ifAvailable--
-      this.replicator.updateAll()
+      this.replicator._maybeResolveAvailable()
       return
     }
 
@@ -2449,16 +2449,33 @@ module.exports = class Replicator {
     this.peers.splice(this.peers.indexOf(peer), 1)
     peer.wants.destroy()
 
-    if (this._manifestPeer === peer) this._manifestPeer = null
+    let needsUpdate = false
+
+    if (this._manifestPeer === peer) {
+      this._manifestPeer = null
+      needsUpdate = true
+    }
 
     for (const req of this._inflight) {
       if (req.peer !== peer) continue
       this._inflight.remove(req.id, true)
       this._clearRequest(peer, req)
+      needsUpdate = true
     }
 
     this._onpeerupdate(false, peer)
-    this.updateAll()
+
+    // A close can also wake pending work that was not assigned to the closing peer.
+    const hasPendingUpdate =
+      needsUpdate ||
+      this._queued.length > 0 ||
+      this._seeks.length > 0 ||
+      this._ranges.length > 0 ||
+      this._reorgs.length > 0 ||
+      this._maybeUpdate()
+
+    if (hasPendingUpdate && this.peers.length > 0) this.updateAll()
+    else this._maybeResolveAvailable()
   }
 
   _queueBlock(b) {
@@ -2668,6 +2685,11 @@ module.exports = class Replicator {
     }
   }
 
+  _maybeResolveAvailable() {
+    this._checkUpgradeIfAvailable()
+    this._maybeResolveIfAvailableRanges()
+  }
+
   _clearRequest(peer, req) {
     if (req.block !== null) {
       this._clearInflightBlock(this._blocks, req)
diff --git a/test/replicate.js b/test/replicate.js
index 20b1b02f..d354c333 100644
--- a/test/replicate.js
+++ b/test/replicate.js
@@ -844,6 +844,55 @@ test('closing peer with inflight block reschedules on remaining peer', async fun
   t.alike(await block, b4a.from('block-0'))
 })
 
+test('closing idle multiplexed stream does not update all peers', async function (t) {
+  const writer = await create(t)
+  await writer.append('block')
+
+  const clone = await create(t, writer.key)
+  const streams = []
+
+  for (let i = 0; i < 3; i++) {
+    const peer = new Promise((resolve) => clone.once('peer-add', resolve))
+    streams.push(replicate(writer, clone, t, { keepAlive: true }))
+    await peer
+  }
+
+  await clone.get(0)
+  await eventFlush()
+
+  t.is(clone.peers.length, 3, 'clone has multiple peers')
+
+  const replicator = clone.core.replicator
+  const updateAll = replicator.updateAll
+  const updatePeer = replicator._updatePeer
+
+  let updates = 0
+  let peerScans = 0
+
+  replicator.updateAll = function () {
+    updates++
+    return updateAll.apply(this, arguments)
+  }
+
+  replicator._updatePeer = function () {
+    peerScans++
+    return updatePeer.apply(this, arguments)
+  }
+
+  t.teardown(() => {
+    replicator.updateAll = updateAll
+    replicator._updatePeer = updatePeer
+  })
+
+  const peerRemoved = new Promise((resolve) => clone.once('peer-remove', resolve))
+  await unreplicate(streams[0])
+  await peerRemoved
+
+  t.is(clone.peers.length, 2, 'clone still has remaining peers')
+  t.is(updates, 0)
+  t.is(peerScans, 0)
+})
+
 test('closing idle peer schedules pending range on remaining peer', async function (t) {
   const writer = await create(t)
   const batch = []