R-1261: the line hold holds every running seeder, drops the record of an app removed while held, and puts back the qBittorrent slot it held (alternative speed). Red-proved. Commit only.

controller/internal/upwatch/linehold.go

@@ -4,6 +4,8 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
+	"net/url"
+	"strings"
 	"time"
 
 	"gitea.dooplex.hu/admin/felhom-controller/internal/logx"
@@ -33,11 +35,12 @@ import (
 // HeldLimit is a torrent app's global upload limit as the app stored it.
 type HeldLimit struct {
 	Bytes   int64 `json:"bytes,omitempty"`   // qBittorrent: B/s, 0 = none
+	Alt     bool  `json:"alt,omitempty"`     // qBittorrent: the ALTERNATIVE speed limit's slot (`alt_up_limit`), else `up_limit`
 	Enabled bool  `json:"enabled,omitempty"` // Transmission: speed-limit-up-enabled
 	KBps    int64 `json:"kbps,omitempty"`    // Transmission: speed-limit-up, kB/s
 }
 
-// LineHold is the record of a held app (settings.json `upwatch.line_test_hold`).
+// LineHold is the record of one held app (settings.json `upwatch.line_test_holds`).
 type LineHold struct {
 	App  string    `json:"app"`
 	Prev HeldLimit `json:"prev"`
@@ -48,11 +51,15 @@ type LineHold struct {
 // Holdable is one torrent app's global upload limit.
 type Holdable interface {
 	Stack() string
+	// ReadLimit reads the limit that applies NOW (qBittorrent: the slot of its current speed mode).
 	ReadLimit(ctx context.Context) (HeldLimit, error)
-	// WriteLimit sets the limit and returns what the app stored.
+	// ReadLimitLike reads the same slot as like, whatever applies now — the release compares and writes the slot it
+	// held, so a household's mode switch during the test never leaves the test value behind (R-1261).
+	ReadLimitLike(ctx context.Context, like HeldLimit) (HeldLimit, error)
+	// WriteLimit sets the limit in l's slot and returns what the app stored there.
 	WriteLimit(ctx context.Context, l HeldLimit) (HeldLimit, error)
-	// HoldValue is the test value: very low, never zero (zero is „no limit").
-	HoldValue() HeldLimit
+	// HoldValue is the test value in prev's slot: very low, never zero (zero is „no limit").
+	HoldValue(prev HeldLimit) HeldLimit
 }
 
 // LineRunResult is the agent's answer to a test on request.
@@ -66,18 +73,49 @@ type LineRunResult struct {
 // holdTimeout bounds each app call made to put a limit back; it is not the caller's context, which may be ending.
 const holdTimeout = 30 * time.Second
 
-func (s *Service) hold() *LineHold {
-	return decode(s.Store.GetUpwatch()).Hold
+// heldList is every hold record, the 0.343.0 single one included (R-1261: a record that version left is honoured).
+func heldList(st State) []LineHold {
+	out := append([]LineHold(nil), st.Holds...)
+	if st.Hold != nil {
+		dup := false
+		for _, h := range out {
+			dup = dup || h.App == st.Hold.App
+		}
+		if !dup {
+			out = append(out, *st.Hold)
+		}
+	}
+	return out
 }
 
-func (s *Service) saveHold(h *LineHold) error {
+func (s *Service) holds() []LineHold {
+	return heldList(decode(s.Store.GetUpwatch()))
+}
+
+// saveHolds stores the full list (nil clears it) and drops the 0.343.0 single record.
+func (s *Service) saveHolds(hs []LineHold) error {
 	return s.Store.UpdateUpwatch(func(old json.RawMessage) (json.RawMessage, error) {
 		st := decode(old)
-		st.Hold = h
+		st.Hold = nil
+		st.Holds = hs
+		if len(hs) == 0 {
+			st.Holds = nil
+		}
 		return json.Marshal(st)
 	})
 }
 
+// dropHold removes one app's record, keeping the others.
+func (s *Service) dropHold(app string) error {
+	var keep []LineHold
+	for _, h := range s.holds() {
+		if h.App != app {
+			keep = append(keep, h)
+		}
+	}
+	return s.saveHolds(keep)
+}
+
 func (s *Service) torrentApp(stack string) Holdable {
 	for _, t := range s.Torrents {
 		if t.Stack() == stack {
@@ -91,32 +129,43 @@ func (s *Service) torrentRunning(stack string) bool {
 	return s.TorrentRunning != nil && s.TorrentRunning(stack)
 }
 
-// RecoverHold puts back a limit a hold left behind (main calls it at start; SeedLineTestNow calls it first). It
-// answers true when no record remains.
-func (s *Service) RecoverHold(ctx context.Context) bool {
-	h := s.hold()
-	if h == nil {
-		return true
-	}
-	app := s.torrentApp(h.App)
-	if app == nil {
-		logx.Warnf(s.Log, "[upwatch] a line-test hold names %q, which this controller cannot reach — record dropped", h.App)
-		return s.saveHold(nil) == nil
-	}
-	if !s.torrentRunning(h.App) {
-		logx.Infof(s.Log, "[upwatch] %s is held at the line-test value but not running — put back when it runs", h.App)
-		return false
-	}
-	logx.Infof(s.Log, "[upwatch] %s was left at the line-test value (since %s) — putting its limit back", h.App, h.At)
-	return s.release(ctx, app, *h)
+func (s *Service) torrentInstalled(stack string) bool {
+	return s.TorrentInstalled == nil || s.TorrentInstalled(stack)
 }
 
-// release puts the old limit back when the app still holds the test value, and clears the record. It keeps the
-// record (answers false) only when the app cannot be read or written: the next tick tries again.
+// RecoverHold puts back every limit a hold left behind (main calls it at start; SeedLineTestNow calls it first). It
+// answers true when no record remains.
+func (s *Service) RecoverHold(ctx context.Context) bool {
+	for _, h := range s.holds() {
+		app := s.torrentApp(h.App)
+		if app == nil {
+			logx.Warnf(s.Log, "[upwatch] a line-test hold names %q, which this controller cannot reach — record dropped", h.App)
+			_ = s.dropHold(h.App)
+			continue
+		}
+		if !s.torrentRunning(h.App) {
+			if !s.torrentInstalled(h.App) {
+				// R-1261: removed while held — there is no limit to put back, and a record kept for it would stop
+				// qBittorrent's 50 % rule for good.
+				logx.Infof(s.Log, "[upwatch] %s was removed while held for the line test — its record is dropped (nothing to put back)", h.App)
+				_ = s.dropHold(h.App)
+				continue
+			}
+			logx.Infof(s.Log, "[upwatch] %s is held at the line-test value but not running — put back when it runs", h.App)
+			continue
+		}
+		logx.Infof(s.Log, "[upwatch] %s was left at the line-test value (since %s) — putting its limit back", h.App, h.At)
+		s.release(ctx, app, h)
+	}
+	return len(s.holds()) == 0
+}
+
+// release puts the old limit back when the app still holds the test value (in the slot it held), and drops this app's
+// record. It keeps the record (answers false) only when the app cannot be read or written: the next tick tries again.
 func (s *Service) release(ctx context.Context, app Holdable, h LineHold) bool {
 	rctx, cancel := context.WithTimeout(context.WithoutCancel(ctx), holdTimeout)
 	defer cancel()
-	cur, err := app.ReadLimit(rctx)
+	cur, err := app.ReadLimitLike(rctx, h.Held)
 	if err != nil {
 		logx.Warnf(s.Log, "[upwatch] %s: reading its limit to put it back: %v — tried again in 15 minutes", h.App, err)
 		return false
@@ -138,58 +187,74 @@ func (s *Service) release(ctx context.Context, app Holdable, h LineHold) bool {
 			logx.Infof(s.Log, "[upwatch] %s's upload limit is back as it was (%+v)", h.App, got)
 		}
 	}
-	if err := s.saveHold(nil); err != nil {
-		logx.Warnf(s.Log, "[upwatch] clearing the line-test hold record: %v", err)
+	if err := s.dropHold(h.App); err != nil {
+		logx.Warnf(s.Log, "[upwatch] clearing the line-test hold record of %s: %v", h.App, err)
 		return false
 	}
 	return true
 }
 
+// releaseAll puts back every app of this hold.
+func (s *Service) releaseAll(ctx context.Context, held []Holdable, hs []LineHold) {
+	for i := range hs {
+		s.release(ctx, held[i], hs[i])
+	}
+}
+
 // SeedLineTestNow runs the hold once when the agent waits for quiet and a torrent app is running (main calls it every
-// 15 minutes, before QBLimitNow). A no-op otherwise.
+// 15 minutes, before QBLimitNow). EVERY running seeder is held — one left seeding keeps the uplink busy and the agent
+// refuses the test „not quiet" every time (R-1261). A no-op otherwise.
 func (s *Service) SeedLineTestNow(ctx context.Context) {
 	if !s.RecoverHold(ctx) || s.LineWaiting == nil || s.LineRun == nil {
 		return
 	}
-	var app Holdable
+	var apps []Holdable
 	for _, t := range s.Torrents {
 		if s.torrentRunning(t.Stack()) {
-			app = t
-			break
+			apps = append(apps, t)
 		}
 	}
-	if app == nil || !s.LineWaiting(ctx) {
+	if len(apps) == 0 || !s.LineWaiting(ctx) {
 		return
 	}
-	prev, err := app.ReadLimit(ctx)
-	if err != nil {
-		logx.Debugf(s.Log, "[upwatch] line test: reading %s's limit: %v — not held", app.Stack(), err)
-		return
-	}
-	h := LineHold{App: app.Stack(), Prev: prev, Held: app.HoldValue(), At: time.Now().UTC().Format(time.RFC3339)}
-	if err := s.saveHold(&h); err != nil {
-		logx.Warnf(s.Log, "[upwatch] line test: saving the hold record: %v — %s not held", err, app.Stack())
-		return
-	}
-	stored, err := app.WriteLimit(ctx, h.Held)
-	if err != nil {
-		// The write may have taken although its read-back failed: release compares against the intended value.
-		logx.Warnf(s.Log, "[upwatch] line test: holding %s: %v — putting it back", app.Stack(), err)
-		s.release(ctx, app, h)
-		return
-	}
-	if stored != h.Held {
-		h.Held = stored
-		if err := s.saveHold(&h); err != nil {
-			logx.Warnf(s.Log, "[upwatch] line test: saving the hold record: %v — putting %s back", err, app.Stack())
-			s.release(ctx, app, h)
+	now := time.Now().UTC().Format(time.RFC3339)
+	hs := make([]LineHold, 0, len(apps))
+	for _, app := range apps {
+		prev, err := app.ReadLimit(ctx)
+		if err != nil {
+			// One seeder that cannot be read cannot be held, and the test would be refused anyway: hold none.
+			logx.Debugf(s.Log, "[upwatch] line test: reading %s's limit: %v — nothing held", app.Stack(), err)
 			return
 		}
+		hs = append(hs, LineHold{App: app.Stack(), Prev: prev, Held: app.HoldValue(prev), At: now})
 	}
-	logx.Infof(s.Log, "[upwatch] line test: %s held at %+v (was %+v) — asking the agent for a test", app.Stack(), stored, prev)
-	// Deferred: a panic in the call puts the limit back too. A killed process does not — that is RecoverHold's.
+	// Every record FIRST, then the apps: a stop between the two finds the record and puts the limit back.
+	if err := s.saveHolds(hs); err != nil {
+		logx.Warnf(s.Log, "[upwatch] line test: saving the hold records: %v — nothing held", err)
+		return
+	}
+	for i, app := range apps {
+		stored, err := app.WriteLimit(ctx, hs[i].Held)
+		if err != nil {
+			// The write may have taken although its read-back failed: release compares against the intended value.
+			logx.Warnf(s.Log, "[upwatch] line test: holding %s: %v — putting every held app back", app.Stack(), err)
+			s.releaseAll(ctx, apps, hs)
+			return
+		}
+		if stored != hs[i].Held {
+			hs[i].Held = stored
+			if err := s.saveHolds(hs); err != nil {
+				logx.Warnf(s.Log, "[upwatch] line test: saving the hold records: %v — putting every held app back", err)
+				s.releaseAll(ctx, apps, hs)
+				return
+			}
+		}
+		logx.Infof(s.Log, "[upwatch] line test: %s held at %+v (was %+v)", app.Stack(), stored, hs[i].Prev)
+	}
+	logx.Infof(s.Log, "[upwatch] line test: %d app(s) held — asking the agent for a test", len(apps))
+	// Deferred: a panic in the call puts the limits back too. A killed process does not — that is RecoverHold's.
 	res, err := func() (LineRunResult, error) {
-		defer s.release(ctx, app, h)
+		defer s.releaseAll(ctx, apps, hs)
 		return s.LineRun(ctx)
 	}()
 	switch {
@@ -207,18 +272,76 @@ func (s *Service) SeedLineTestNow(ctx context.Context) {
 
 // ── the two torrent apps ─────────────────────────────────────────────────────────────────────────────────────────
 
+// qBittorrent's limit calls (transfer/uploadLimit, setUploadLimit) act on the slot of its CURRENT speed mode — measured
+// on 5.2.4 (felhom.eu `audits/night-2026-10-25/r1261-qbittorrent-api-measured.txt`): in alternative mode they read and
+// write `alt_up_limit`. The hold therefore names its slot and reads/writes it through app/preferences (`up_limit`,
+// `alt_up_limit`, both B/s, either writable in either mode), so a mode switch during the test cannot leave 1 KiB/s.
+
 func (q *QBittorrent) ReadLimit(ctx context.Context) (HeldLimit, error) {
-	b, err := q.UploadLimit(ctx, nil)
-	return HeldLimit{Bytes: b}, err
+	h, err := q.session(ctx, true)
+	if err != nil {
+		return HeldLimit{}, err
+	}
+	code, b, _, err := httpDo(ctx, q.client(), "GET", q.base()+"/api/v2/transfer/speedLimitsMode", h, nil, "")
+	if err != nil || code != 200 {
+		return HeldLimit{}, fmt.Errorf("qBittorrent speedLimitsMode: HTTP %d %v", code, err)
+	}
+	return q.readSlot(ctx, h, strings.TrimSpace(string(b)) == "1")
+}
+
+func (q *QBittorrent) ReadLimitLike(ctx context.Context, like HeldLimit) (HeldLimit, error) {
+	h, err := q.session(ctx, true)
+	if err != nil {
+		return HeldLimit{}, err
+	}
+	return q.readSlot(ctx, h, like.Alt)
+}
+
+func qbSlotKey(alt bool) string {
+	if alt {
+		return "alt_up_limit"
+	}
+	return "up_limit"
+}
+
+func (q *QBittorrent) readSlot(ctx context.Context, h map[string]string, alt bool) (HeldLimit, error) {
+	code, b, _, err := httpDo(ctx, q.client(), "GET", q.base()+"/api/v2/app/preferences", h, nil, "")
+	if err != nil || code != 200 {
+		return HeldLimit{}, fmt.Errorf("qBittorrent preferences: HTTP %d %v", code, err)
+	}
+	var prefs map[string]json.RawMessage
+	if err := json.Unmarshal(b, &prefs); err != nil {
+		return HeldLimit{}, fmt.Errorf("qBittorrent preferences: %v", err)
+	}
+	raw, ok := prefs[qbSlotKey(alt)]
+	if !ok {
+		return HeldLimit{}, fmt.Errorf("qBittorrent preferences: no %s", qbSlotKey(alt))
+	}
+	var v int64
+	if err := json.Unmarshal(raw, &v); err != nil {
+		return HeldLimit{}, fmt.Errorf("qBittorrent preferences %s: %q", qbSlotKey(alt), raw)
+	}
+	return HeldLimit{Bytes: v, Alt: alt}, nil
 }
 
 func (q *QBittorrent) WriteLimit(ctx context.Context, l HeldLimit) (HeldLimit, error) {
-	b, err := q.SetUploadLimit(ctx, l.Bytes)
-	return HeldLimit{Bytes: b}, err
+	h, err := q.session(ctx, true)
+	if err != nil {
+		return HeldLimit{}, err
+	}
+	js, _ := json.Marshal(map[string]int64{qbSlotKey(l.Alt): l.Bytes})
+	form := url.Values{"json": {string(js)}}.Encode()
+	code, _, _, err := httpDo(ctx, q.client(), "POST", q.base()+"/api/v2/app/setPreferences", h, []byte(form), "application/x-www-form-urlencoded")
+	if err != nil || code != 200 {
+		return HeldLimit{}, fmt.Errorf("qBittorrent setPreferences %s: HTTP %d %v", qbSlotKey(l.Alt), code, err)
+	}
+	return q.readSlot(ctx, h, l.Alt)
 }
 
-// HoldValue: 1 KiB/s, qBittorrent's smallest stored step.
-func (q *QBittorrent) HoldValue() HeldLimit { return HeldLimit{Bytes: 1024} }
+// HoldValue: 1 KiB/s in the slot that applied when the hold began.
+func (q *QBittorrent) HoldValue(prev HeldLimit) HeldLimit {
+	return HeldLimit{Bytes: 1024, Alt: prev.Alt}
+}
 
 func (t *Transmission) ReadLimit(ctx context.Context) (HeldLimit, error) {
 	var st struct {
@@ -245,5 +368,10 @@ func (t *Transmission) WriteLimit(ctx context.Context, l HeldLimit) (HeldLimit,
 	return t.ReadLimit(ctx)
 }
 
+// ReadLimitLike: Transmission's speed-limit-up is one slot (its alternative speed has its own fields, never touched).
+func (t *Transmission) ReadLimitLike(ctx context.Context, _ HeldLimit) (HeldLimit, error) {
+	return t.ReadLimit(ctx)
+}
+
 // HoldValue: 1 kB/s with the limit switched on.
-func (t *Transmission) HoldValue() HeldLimit { return HeldLimit{Enabled: true, KBps: 1} }
+func (t *Transmission) HoldValue(HeldLimit) HeldLimit { return HeldLimit{Enabled: true, KBps: 1} }

controller/internal/upwatch/linehold_r1261_test.go

@@ -0,0 +1,190 @@
+package upwatch
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+)
+
+// fakeQBPrefs is qBittorrent 5.2.4's limit API as measured on 2026-10-25 (felhom.eu
+// `audits/night-2026-10-25/r1261-qbittorrent-api-measured.txt`): transfer/uploadLimit and setUploadLimit act on the
+// slot of the CURRENT speed mode (setUploadLimit rounds to whole KiB); app/preferences shows up_limit and alt_up_limit
+// in B/s; app/setPreferences writes either slot exactly, in either mode.
+type fakeQBPrefs struct {
+	up, alt int64
+	altMode bool
+}
+
+func (f *fakeQBPrefs) server(t *testing.T, pw string) *httptest.Server {
+	var srv *httptest.Server
+	srv = httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.URL.Path == "/api/v2/auth/login" {
+			r.ParseForm()
+			if r.Header.Get("Referer") != srv.URL || r.Form.Get("password") != pw {
+				w.WriteHeader(401)
+				return
+			}
+			http.SetCookie(w, &http.Cookie{Name: "QBT_SID_8080", Value: "s1"})
+			w.WriteHeader(204)
+			return
+		}
+		active := &f.up
+		if f.altMode {
+			active = &f.alt
+		}
+		switch r.URL.Path {
+		case "/api/v2/transfer/speedLimitsMode":
+			if f.altMode {
+				fmt.Fprint(w, "1")
+			} else {
+				fmt.Fprint(w, "0")
+			}
+		case "/api/v2/transfer/toggleSpeedLimitsMode":
+			f.altMode = !f.altMode
+		case "/api/v2/transfer/uploadLimit":
+			fmt.Fprint(w, *active)
+		case "/api/v2/transfer/setUploadLimit":
+			r.ParseForm()
+			var v int64
+			fmt.Sscan(r.Form.Get("limit"), &v)
+			*active = v / 1024 * 1024
+		case "/api/v2/app/preferences":
+			json.NewEncoder(w).Encode(map[string]any{"up_limit": f.up, "alt_up_limit": f.alt, "scheduler_enabled": false})
+		case "/api/v2/app/setPreferences":
+			r.ParseForm()
+			var m map[string]int64
+			if err := json.Unmarshal([]byte(r.Form.Get("json")), &m); err != nil {
+				w.WriteHeader(400)
+				return
+			}
+			if v, ok := m["up_limit"]; ok {
+				f.up = v
+			}
+			if v, ok := m["alt_up_limit"]; ok {
+				f.alt = v
+			}
+		default:
+			w.WriteHeader(404)
+		}
+	}))
+	return srv
+}
+
+// R-1261 edge 1: two seeders behind one uplink. Holding only the first left the second seeding, so the agent refused
+// the test „not quiet" every 15 minutes and it was never counted.
+// RED-PROOF: hold only the first running app (the 0.343.0 loop's `break`) → the second is never held → fails.
+func TestR1261_EverySeederIsHeldAndEveryLimitComesBack(t *testing.T) {
+	qb := &fakeTorrent{limit: HeldLimit{Bytes: 2_499_584}}
+	tr := &fakeTorrent{name: "transmission", limit: HeldLimit{Enabled: true, KBps: 500}}
+	store := &memStore{}
+	runs := 0
+	svc := &Service{Store: store, Torrents: []Holdable{qb, tr},
+		TorrentRunning: func(string) bool { return true },
+		LineWaiting:    func(context.Context) bool { return true },
+		LineRun: func(context.Context) (LineRunResult, error) {
+			runs++
+			if qb.limit != (HeldLimit{Bytes: 1024}) || tr.limit != (HeldLimit{Bytes: 1024}) {
+				t.Fatalf("during the test qbittorrent=%+v transmission=%+v — every seeder must be at the test value", qb.limit, tr.limit)
+			}
+			if n := len(heldList(decode(store.GetUpwatch()))); n != 2 {
+				t.Fatalf("during the test %d record(s), want 2 — a restart now could not put both back", n)
+			}
+			return LineRunResult{OK: true, Mbps: 92}, nil
+		}}
+	svc.SeedLineTestNow(context.Background())
+	if runs != 1 {
+		t.Fatalf("agent asked %d times, want 1", runs)
+	}
+	if qb.limit != (HeldLimit{Bytes: 2_499_584}) || tr.limit != (HeldLimit{Enabled: true, KBps: 500}) {
+		t.Fatalf("after the test qbittorrent=%+v transmission=%+v, want both limits back", qb.limit, tr.limit)
+	}
+	if n := len(heldList(decode(store.GetUpwatch()))); n != 0 {
+		t.Fatalf("%d record(s) left after the test", n)
+	}
+}
+
+// R-1261 edge 2: an app removed while held. The record was kept „until it runs" — forever — and qBittorrent's 50 %
+// rule never ran again. The consequence asserted: the record goes, and the next hold can run.
+// RED-PROOF: drop the TorrentInstalled check in RecoverHold → the record stays, no test runs → fails.
+func TestR1261_ARecordOfAnAppRemovedWhileHeldIsDropped(t *testing.T) {
+	r := newHoldRig(t)
+	r.store.UpdateUpwatch(func(json.RawMessage) (json.RawMessage, error) {
+		return json.Marshal(State{Holds: []LineHold{{App: "qbittorrent", Prev: HeldLimit{Bytes: 2_499_584}, Held: HeldLimit{Bytes: 1024}}}})
+	})
+	r.running = false
+	installed := false
+	r.svc.TorrentInstalled = func(string) bool { return installed }
+	if !r.svc.RecoverHold(context.Background()) || r.record() != nil {
+		t.Fatalf("the record of a removed app must be dropped, got %+v", r.record())
+	}
+	// Still installed but stopped: the record is kept for when it runs again (the old rule, unchanged).
+	r.store.UpdateUpwatch(func(json.RawMessage) (json.RawMessage, error) {
+		return json.Marshal(State{Holds: []LineHold{{App: "qbittorrent", Prev: HeldLimit{Bytes: 2_499_584}, Held: HeldLimit{Bytes: 1024}}}})
+	})
+	installed = true
+	if r.svc.RecoverHold(context.Background()) || r.record() == nil {
+		t.Fatal("a stopped but installed app keeps its record")
+	}
+	// The app is reinstalled and runs: the hold runs again (the next weekly test is no longer blocked).
+	r.store.UpdateUpwatch(func(json.RawMessage) (json.RawMessage, error) { return json.Marshal(State{}) })
+	r.running = true
+	r.svc.SeedLineTestNow(context.Background())
+	if r.runs != 1 {
+		t.Fatalf("after the record is gone the line test runs again; runs=%d", r.runs)
+	}
+}
+
+// R-1261 edge 3: the household switches qBittorrent to its alternative speed during the test. transfer/uploadLimit
+// then reads the ALTERNATIVE slot, the release took it for „the household's change", and the normal slot kept 1 KiB/s.
+// Now the hold names its slot and the release reads and writes that slot.
+// RED-PROOF: read the current mode's slot in ReadLimitLike (the old behaviour) → up_limit stays 1024 → fails.
+func TestR1261_ASpeedModeSwitchDuringTheTestNeverLeavesTheTestValue(t *testing.T) {
+	for _, startAlt := range []bool{false, true} {
+		t.Run(fmt.Sprintf("hold in alt mode=%v", startAlt), func(t *testing.T) {
+			fq := &fakeQBPrefs{up: 2_499_584, alt: 3_072_000, altMode: startAlt}
+			srv := fq.server(t, "pw-canary")
+			defer srv.Close()
+			qb := &QBittorrent{Box: envBox{"qbittorrent/QBT_ADMIN_PASSWORD": "pw-canary"}, URL: srv.URL}
+			store := &memStore{}
+			svc := &Service{Store: store, Torrents: []Holdable{qb},
+				TorrentRunning: func(string) bool { return true },
+				LineWaiting:    func(context.Context) bool { return true },
+				LineRun: func(context.Context) (LineRunResult, error) {
+					held := fq.up
+					if startAlt {
+						held = fq.alt
+					}
+					if held != 1024 {
+						t.Fatalf("during the test the active slot holds %d, want 1024", held)
+					}
+					fq.altMode = !fq.altMode // the household presses the turtle
+					return LineRunResult{OK: true, Mbps: 92}, nil
+				}}
+			svc.SeedLineTestNow(context.Background())
+			if fq.up != 2_499_584 || fq.alt != 3_072_000 {
+				t.Fatalf("after the test up_limit=%d alt_up_limit=%d, want 2499584 and 3072000 — never the 1 KiB/s test value", fq.up, fq.alt)
+			}
+			if n := len(heldList(decode(store.GetUpwatch()))); n != 0 {
+				t.Fatalf("%d record(s) left", n)
+			}
+		})
+	}
+}
+
+// A record that controller 0.343.0 left (the single `line_test_hold`) is honoured and cleared.
+func TestR1261_ARecordThe0343ControllerLeftIsPutBack(t *testing.T) {
+	r := newHoldRig(t)
+	r.app.limit = HeldLimit{Bytes: 1024}
+	r.store.UpdateUpwatch(func(json.RawMessage) (json.RawMessage, error) {
+		return json.Marshal(State{Hold: &LineHold{App: "qbittorrent", Prev: HeldLimit{Bytes: 2_499_584}, Held: HeldLimit{Bytes: 1024}}})
+	})
+	if !r.svc.RecoverHold(context.Background()) || r.app.limit != (HeldLimit{Bytes: 2_499_584}) {
+		t.Fatalf("limit %+v, want the 0.343.0 record's limit back", r.app.limit)
+	}
+	if st := decode(r.store.GetUpwatch()); st.Hold != nil || len(st.Holds) != 0 {
+		t.Fatalf("the old record must be cleared, got %+v", st)
+	}
+}

controller/internal/upwatch/linehold_test.go

@@ -15,20 +15,29 @@ import (
 // fakeTorrent is a torrent app's limit in memory. failWrite fails the next write AFTER storing it (a write that
 // took while its read-back failed); failRead fails reads.
 type fakeTorrent struct {
+	name      string // "" = qbittorrent
 	limit     HeldLimit
 	writes    []HeldLimit
 	failWrite bool
 	failRead  bool
 }
 
-func (f *fakeTorrent) Stack() string        { return "qbittorrent" }
-func (f *fakeTorrent) HoldValue() HeldLimit { return HeldLimit{Bytes: 1024} }
+func (f *fakeTorrent) Stack() string {
+	if f.name != "" {
+		return f.name
+	}
+	return "qbittorrent"
+}
+func (f *fakeTorrent) HoldValue(HeldLimit) HeldLimit { return HeldLimit{Bytes: 1024} }
 func (f *fakeTorrent) ReadLimit(context.Context) (HeldLimit, error) {
 	if f.failRead {
 		return HeldLimit{}, errors.New("connection refused")
 	}
 	return f.limit, nil
 }
+func (f *fakeTorrent) ReadLimitLike(ctx context.Context, _ HeldLimit) (HeldLimit, error) {
+	return f.ReadLimit(ctx)
+}
 func (f *fakeTorrent) WriteLimit(_ context.Context, l HeldLimit) (HeldLimit, error) {
 	f.limit = l
 	f.writes = append(f.writes, l)
@@ -68,7 +77,14 @@ func newHoldRig(t *testing.T) *holdRig {
 	return r
 }
 
-func (r *holdRig) record() *LineHold { return decode(r.store.GetUpwatch()).Hold }
+// record is the single held app's record (nil when none) — the rigs below hold one app unless they say otherwise.
+func (r *holdRig) record() *LineHold {
+	hs := heldList(decode(r.store.GetUpwatch()))
+	if len(hs) == 0 {
+		return nil
+	}
+	return &hs[0]
+}
 
 // R-1250, the brief's three cases: the old limit — the household's own — comes back exactly after a measured test,
 // after a failed one, and after a refused one; during the test the app holds the test value and the record exists.
@@ -237,15 +253,19 @@ func TestHold_QBLimitRuleSkipsAHeldLimit(t *testing.T) {
 // The two apps' real APIs: qBittorrent's global limit, Transmission's session-get/session-set with the session-id
 // handshake. The test value is never zero (zero is „no limit").
 func TestHold_TheTwoAppsReadAndWriteTheirLimit(t *testing.T) {
-	logins, expire, limit := 0, false, int64(2_499_584)
-	srv := fakeQBServer(t, "pw-canary", &logins, &expire, &limit)
+	fq := &fakeQBPrefs{up: 2_499_584, alt: 10_240}
+	srv := fq.server(t, "pw-canary")
 	defer srv.Close()
 	qb := &QBittorrent{Box: envBox{"qbittorrent/QBT_ADMIN_PASSWORD": "pw-canary"}, URL: srv.URL}
-	if l, err := qb.ReadLimit(context.Background()); err != nil || l.Bytes != 2_499_584 {
+	if l, err := qb.ReadLimit(context.Background()); err != nil || l != (HeldLimit{Bytes: 2_499_584}) {
 		t.Fatalf("qBittorrent read %+v %v", l, err)
 	}
-	if l, err := qb.WriteLimit(context.Background(), qb.HoldValue()); err != nil || l != (HeldLimit{Bytes: 1024}) || limit != 1024 {
-		t.Fatalf("qBittorrent hold: %+v %v, stored %d", l, err, limit)
+	if l, err := qb.WriteLimit(context.Background(), qb.HoldValue(HeldLimit{})); err != nil || l != (HeldLimit{Bytes: 1024}) || fq.up != 1024 {
+		t.Fatalf("qBittorrent hold: %+v %v, stored %d", l, err, fq.up)
+	}
+	fq.altMode = true
+	if l, err := qb.ReadLimit(context.Background()); err != nil || l != (HeldLimit{Bytes: 10_240, Alt: true}) {
+		t.Fatalf("qBittorrent read in alternative mode %+v %v, want the alt slot", l, err)
 	}
 
 	tr := struct {
@@ -289,7 +309,7 @@ func TestHold_TheTwoAppsReadAndWriteTheirLimit(t *testing.T) {
 	if err != nil || prev != (HeldLimit{KBps: 500}) {
 		t.Fatalf("Transmission read %+v %v, want 500 kB/s switched off", prev, err)
 	}
-	if l, err := tm.WriteLimit(context.Background(), tm.HoldValue()); err != nil || l != (HeldLimit{Enabled: true, KBps: 1}) {
+	if l, err := tm.WriteLimit(context.Background(), tm.HoldValue(HeldLimit{})); err != nil || l != (HeldLimit{Enabled: true, KBps: 1}) {
 		t.Fatalf("Transmission hold: %+v %v", l, err)
 	}
 	if l, err := tm.WriteLimit(context.Background(), prev); err != nil || l != prev || tr.enabled || tr.up != 500 {

controller/internal/upwatch/service.go

@@ -14,8 +14,10 @@ import (
 type State struct {
 	Line    []LineRecord  `json:"line,omitempty"`
 	QBLimit *QBLimitState `json:"qb_limit,omitempty"`
-	// Hold is a torrent app held low for a line test on request (R-1250, linehold.go); nil when none.
+	// Hold is the ONE held app of controller 0.343.0 (R-1250); read for a record that version left, never written.
 	Hold *LineHold `json:"line_test_hold,omitempty"`
+	// Holds are the torrent apps held low for a line test on request — every running seeder (R-1261, linehold.go).
+	Holds []LineHold `json:"line_test_holds,omitempty"`
 }
 
 // Store is the settings half the service needs (settings.Settings satisfies it).
@@ -46,14 +48,16 @@ type Service struct {
 	// to ep0 inside the tunnel. nil or ok=false = not measured. Read every 15 minutes (RefreshMeasured), never per
 	// minute.
 	Measured func(ctx context.Context) (mbps float64, at time.Time, ok bool)
-	// The line test for a box that seeds all day (R-1250, linehold.go). Torrents are the apps that can be held, in
-	// order of preference; TorrentRunning says whether one runs now; LineWaiting is the agent's waiting_for_quiet;
-	// LineRun is its test on request. Any nil = no hold.
-	Torrents       []Holdable
-	TorrentRunning func(stack string) bool
-	LineWaiting    func(ctx context.Context) bool
-	LineRun        func(ctx context.Context) (LineRunResult, error)
-	Log            *log.Logger
+	// The line test for a box that seeds all day (R-1250, linehold.go). Torrents are the apps that can be held;
+	// TorrentRunning says whether one runs now; TorrentInstalled whether it is installed at all (a hold of an app
+	// removed while held is dropped — R-1261; nil = assume installed); LineWaiting is the agent's waiting_for_quiet;
+	// LineRun is its test on request. Any of Torrents/TorrentRunning/LineWaiting/LineRun nil = no hold.
+	Torrents         []Holdable
+	TorrentRunning   func(stack string) bool
+	TorrentInstalled func(stack string) bool
+	LineWaiting      func(ctx context.Context) bool
+	LineRun          func(ctx context.Context) (LineRunResult, error)
+	Log              *log.Logger
 
 	mu         sync.Mutex
 	measured   float64
@@ -146,7 +150,7 @@ func (s *Service) QBLimitNow(ctx context.Context) {
 	s.RefreshMeasured(ctx)
 	line, known := s.MeasuredLine()
 	cur := decode(s.Store.GetUpwatch())
-	if cur.Hold != nil {
+	if len(heldList(cur)) > 0 {
 		// A line-test hold is in place or was left behind: qBittorrent holds the test value, which the rule would
 		// read as the household's change and then never touch the limit again (linehold.go).
 		logx.Debugf(s.Log, "[upwatch] qBittorrent limit: a line-test hold record exists — rule skipped until it is cleared")