Merge pull request 'mesh-grants keeps what the bus loaded while it composes only part of the mesh (issue 1966, bootstrap recovery)' (#171) from fix/1966-grants-keeps-what-is-loaded into main

modules/mesh-grants/grants_test.go

@@ -2414,9 +2414,15 @@ func TestGrants(t *testing.T) {
 		b.loaded = append(b.loaded, grants.User{User: "c.old"})
 		b.put(grants.ReadHave, "b.mod-y", runs)
 		hash("b.mod-y")
-		if res := p.Compose(); res.Sealed == nil || !strings.Contains(res.Sealed.Why, "would drop c.old of the list in force") {
+		if res := p.Compose(); res.Sealed == nil || !strings.Contains(res.Sealed.Why, "would take from loaded users: c.old (left out)") ||
+			!slices.Contains(res.KeptLoaded, "c.old") {
 			t.Errorf("a list dropping a loaded user was not held: %+v", res.Sealed)
 		}
+		// With its hash, the loaded user the haves do not compose is kept as the loaded list gives it, and the list sealed.
+		hash("c.old")
+		if res := p.Compose(); res.Sealed == nil || res.Sealed.Why != "" || !strings.Contains(string(b.own[grants.StateUserList][grants.KeyWrittenUsers]), `"c.old"`) {
+			t.Errorf("the loaded user was not kept in the list sealed: %+v", res.Sealed)
+		}
 		// The view answers: the assignments alone places again.
 		delete(b.refused, grants.ReadAssignments)
 		if in := grants.ReadInputs(b, &grants.Manifests{}); in.ByHaves != "" || slices.Contains(in.Assigned["a"], "mesh-delivery-assigner") {
@@ -2424,6 +2430,184 @@ func TestGrants(t *testing.T) {
 		}
 	})
 
+	// Issue 1966, the list sealed 2026-11-07 23:09: composed from the bootstrapped seats alone, it took the node seats from the
+	// tool runners, the vault's reads from the node-engines, the seat queues from the build modules, and left out the ledger
+	// account of a held module. A pass that composes part of the mesh (the seat list unread, or placed by the haves) seals
+	// each user of the loaded list and of the list in force with the union of what it composes and what those give it, so it
+	// only adds (the indexer's serving of mesh-catalog included); one that would still take a permission is held, naming it.
+	t.Run("a pass composing part of the mesh keeps what the bus loaded, adding only (issue 1966)", func(t *testing.T) {
+		indexer, err := os.ReadFile("../mesh-delivery-indexer/module.json")
+		if err != nil {
+			t.Fatal(err)
+		}
+		const (
+			nodeSeat  = "mesh.seat.node-files.call.*.a.*"
+			vaultRead = "$JS.API.DIRECT.GET.KV_mesh-vault_signers.>"
+			buildPull = "$JS.API.CONSUMER.MSG.NEXT.SEAT_NODE_BUILD_GO.workers"
+		)
+		ledgerX := strings.Replace(xManifest, `"state"`, `"requires":[{"name":"records","storage":"ledger","template":"ledger",`+
+			`"types":[{"name":"decision","schema":{},"operations":[{"name":"propose","effect":"set-fields"}]}]}],"state"`, 1)
+		catalogSeat := func(s string) bool { return strings.HasPrefix(s, "mesh.seat.mesh-catalog.") }
+		// Review round 1: the list in force gives a wide publish and a deny, the pass composes the user narrower with the
+		// composer's empty deny: the user kept keeps the deny, and dropping it counts as a loss.
+		for _, d := range []struct {
+			name           string
+			composed, kept grants.User
+			loss           string
+		}{
+			{"a deny of the list in force is kept",
+				grants.User{User: "a.mod-v", Publish: []string{"mesh.a"}, Subscribe: []string{}, PublishDeny: []string{}},
+				grants.User{User: "a.mod-v", Publish: []string{"mesh.>", "mesh.a"}, Subscribe: []string{}, PublishDeny: []string{"mesh.seat.mesh-vault.desk.>"}},
+				"deny dropped mesh.seat.mesh-vault.desk.>"},
+			{"a deny the pass composes is kept beside it",
+				grants.User{User: "a.mod-v", Publish: []string{"mesh.a"}, Subscribe: []string{}, PublishDeny: []string{"mesh.b"}},
+				grants.User{User: "a.mod-v", Publish: []string{"mesh.>", "mesh.a"}, Subscribe: []string{}, PublishDeny: []string{"mesh.b", "mesh.seat.mesh-vault.desk.>"}},
+				"deny mesh.b"},
+		} {
+			inForce := grants.User{User: "a.mod-v", Publish: []string{"mesh.>"}, Subscribe: []string{}, PublishDeny: []string{"mesh.seat.mesh-vault.desk.>"}}
+			got := grants.KeepLoaded([]grants.User{d.composed}, nil, map[string]grants.User{"a.mod-v": inForce})["a.mod-v"]
+			if !slices.Equal(got.Publish, d.kept.Publish) || !slices.Equal(got.PublishDeny, d.kept.PublishDeny) {
+				t.Errorf("%s: kept %+v, want %+v", d.name, got, d.kept)
+			}
+			if !slices.Contains(grants.Losses(d.composed, inForce), d.loss) {
+				t.Errorf("%s: losses %v name no %q", d.name, grants.Losses(d.composed, inForce), d.loss)
+			}
+		}
+		for _, row := range []struct {
+			name string
+			bend func(*fakeBus, *grants.Part)
+			// held is what the pass's sealed says it holds, "" when it seals.
+			held string
+		}{
+			{"the seat list unread", func(b *fakeBus, p *grants.Part) {
+				p.SeatList = &seatGate{bootstrapped: []string{meshbroker.Seat, meshcatalog.Seat}}
+			}, ""},
+			{"placed by the haves", func(b *fakeBus, p *grants.Part) {
+				b.refused[grants.ReadAssignments] = true
+				runs := nodeengine.HaveByNodeModuleValue{V: keys.Version, Phase: nodeengineclient.PhaseRunning, Health: nodeengineclient.HealthOK}
+				b.put(grants.ReadHave, "a.mod-x", runs)
+				b.put(grants.ReadHave, "b.mod-y", runs)
+				b.put(grants.ReadHave, "a.mesh-delivery-indexer", runs)
+			}, ""},
+			// The ledger of a held module stays with its module's users, whatever the seat list (held.go).
+			{"the ledger of a module whose manifest is refused", func(b *fakeBus, p *grants.Part) {
+				b.refuse("mod-x", ledgerX, "it is held")
+			}, ""},
+			// The union cannot give a login a loaded user has no hash for: held, naming it.
+			{"a loaded user with no hash, the seat list unread", func(b *fakeBus, p *grants.Part) {
+				p.SeatList = &seatGate{bootstrapped: []string{meshbroker.Seat, meshcatalog.Seat}}
+				delete(b.states[grants.ReadAccounts], "b.mod-y")
+			}, "would take from loaded users: b.mod-y (left out)"},
+		} {
+			t.Run(row.name, func(t *testing.T) {
+				b := fixture()
+				b.manifestOf("mod-x", ledgerX)
+				b.manifestOf("mesh-delivery-indexer", string(indexer))
+				b.assign("a", "mesh-delivery-indexer")
+				busKey, err := seal.GenerateKeyPair()
+				if err != nil {
+					t.Fatal(err)
+				}
+				b.put(grants.ReadHave, "a.nats", nodeengine.HaveByNodeModuleValue{V: keys.Version, Phase: nodeengineclient.PhaseRunning, Health: nodeengineclient.HealthOK,
+					UserList: &nodeengine.UserListWritten{Source: grantsstate.GrantsUserListSource, Revision: 8, Wanted: "sha256:aa", Digest: "sha256:aa", Users: 5,
+						Key: busKey.PublicKey, Follows: grantsstate.FollowGrants}})
+				whole := shadowOf(t, b)
+				for _, u := range whole {
+					b.put(grants.ReadAccounts, u.User, map[string]any{"user": u.User, "hash": "$2a$10$x", "generation": 1, "fingerprint": "sha256:1"})
+				}
+				p := partOn(b)
+				p.Objects = &fakeObjects{}
+				// The list in force, composed whole.
+				p.Compose()
+				if g, _, _ := p.Sealed(); g.Digest == "" {
+					t.Fatal("no list in force sealed")
+				}
+				// The indexer's membership as published serves a tool more than any pass composes now (a tool runner's
+				// seat, say): a pass composing part of the mesh keeps it as published, a whole one publishes what it composes.
+				const extra = `{"subject":"mesh.tools.a.mesh-delivery-indexer.extra"}`
+				{
+					var m map[string]any
+					if err := json.Unmarshal(b.own[grants.StateMemberships]["a.mesh-delivery-indexer"], &m); err != nil {
+						t.Fatal(err)
+					}
+					var e any
+					_ = json.Unmarshal([]byte(extra), &e)
+					m["serves"] = append(m["serves"].([]any), e)
+					b.own[grants.StateMemberships]["a.mesh-delivery-indexer"], _ = json.Marshal(m)
+				}
+				servesExtra := func() bool {
+					return strings.Contains(string(b.own[grants.StateMemberships]["a.mesh-delivery-indexer"]), "mesh-delivery-indexer.extra")
+				}
+				// The bus loaded it with what a whole seat list gives besides, and without the indexer's serving yet.
+				var loaded []grants.User
+				for _, u := range whole {
+					switch u.User {
+					case "a.mod-x":
+						u.Subscribe = append(slices.Clone(u.Subscribe), nodeSeat)
+					case "node.a":
+						u.Subscribe = append(slices.Clone(u.Subscribe), vaultRead)
+					case "b.mod-y":
+						u.Publish = append(slices.Clone(u.Publish), buildPull)
+					case "a.mesh-delivery-indexer":
+						u.Subscribe = slices.DeleteFunc(slices.Clone(u.Subscribe), catalogSeat)
+					}
+					loaded = append(loaded, u)
+				}
+				if !slices.ContainsFunc(loaded, func(u grants.User) bool { return u.User == "ledger.a.mod-x" }) {
+					t.Fatalf("the fixture composes no ledger user: %v", names(loaded))
+				}
+				b.loaded = loaded
+				row.bend(b, p)
+				res := p.Compose()
+				if g, _, _ := p.Sealed(); true {
+					t.Logf("sealed %d users (%s), kept with the loaded list's grants %v, said %q", g.Users, short(g.Digest), res.KeptLoaded, res.Sealed.Why)
+				}
+				partial := row.name != "the ledger of a module whose manifest is refused"
+				if servesExtra() != partial || partial != slices.ContainsFunc(res.NotPublished, func(n string) bool {
+					return strings.HasPrefix(n, "a.mesh-delivery-indexer: kept as published: ") && strings.Contains(n, "mesh-delivery-indexer.extra")
+				}) {
+					t.Errorf("the published membership serving more: kept %v in a pass composing part of the mesh %v; not published %v", servesExtra(), partial, res.NotPublished)
+				}
+				if row.held != "" {
+					if res.Sealed == nil || !strings.Contains(res.Sealed.Why, row.held) {
+						t.Fatalf("not held for %q: %+v", row.held, res.Sealed)
+					}
+					return
+				}
+				g, _, _ := p.Sealed()
+				if res.Sealed == nil || res.Sealed.Why != "" || g.Digest == "" {
+					t.Fatalf("not sealed: %+v (kept %v, refused %v)", res.Sealed, res.KeptLoaded, res.Refused)
+				}
+				sealedAs := func(user string) (grants.User, bool) {
+					raw, _, ok, _ := b.ownGet(grants.StateUserList, grants.SealedUserKey(g.Digest, user))
+					var u grants.User
+					return u, ok && json.Unmarshal(raw, &u) == nil
+				}
+				if row.name == "the ledger of a module whose manifest is refused" {
+					// The seat list read, the pass composes the whole mesh and keeps no loaded permission beyond it; the held
+					// module's users, its ledger's among them, stay as the list in force holds them.
+					if u, ok := sealedAs("ledger.a.mod-x"); !ok || len(grants.Losses(u, whole[slices.IndexFunc(whole, func(u grants.User) bool { return u.User == "ledger.a.mod-x" })])) > 0 {
+						t.Errorf("the held module's ledger account is not kept: %+v (%v)", u, ok)
+					}
+					return
+				}
+				for _, l := range loaded {
+					u, ok := sealedAs(l.User)
+					if !ok {
+						t.Errorf("%s of the loaded list is not in the list sealed", l.User)
+						continue
+					}
+					if lost := grants.Losses(u, l); len(lost) > 0 {
+						t.Errorf("%s loses %v in the list sealed", l.User, lost)
+					}
+				}
+				if ix, _ := sealedAs("a.mesh-delivery-indexer"); !slices.ContainsFunc(ix.Subscribe, catalogSeat) {
+					t.Errorf("the indexer does not gain its serving of mesh-catalog: %v", ix.Subscribe)
+				}
+			})
+		}
+	})
+
 	// ADR 0590 clause 5's test for this repository (issue 1126): no module.json here names mesh-controller, the lease
 	// read and the builder's consume of artifacts-gone included. Read as text, as mesh-catalog's controllerdeps check reads
 	// its own: mesh-sdk names no module, so it holds no such check (issue 774, the operator 2026-11-03).
@@ -3657,3 +3841,7 @@ func (g *seatGate) MayAct(seats ...string) bool {
 	}
 	return true
 }
+
+func short(d string) string {
+	return strings.TrimPrefix(d, "sha256:")[:min(12, len(strings.TrimPrefix(d, "sha256:")))]
+}

modules/mesh-grants/internal/grants/held.go

@@ -26,7 +26,8 @@ const HeldModuleCondition = "mesh-grants.module-held"
 
 // heldModuleUsers are, by user, why it is kept: the users of candidates (the ones the list in force and the bus carry) that
 // belong to a module placed on a node whose manifest the indexer holds (in.Refused) and whose want names no build. A user of
-// a module on a node is `<node>.<module>` or `<node>.<module>.<process>` (buscompose.Principal.Username). Pure.
+// a module on a node is `<node>.<module>`, `<node>.<module>.<process>` or its ledger's `ledger.<node>.<module>`
+// (buscompose.Principal.Username). Pure.
 func heldModuleUsers(in Inputs, candidates []string) map[string]string {
 	held := map[string]string{}
 	for _, g := range in.Refused {
@@ -55,7 +56,8 @@ func heldModuleUsers(in Inputs, candidates []string) map[string]string {
 				state = "unreadable"
 			}
 			for _, user := range candidates {
-				if user == prefix || strings.HasPrefix(user, prefix+".") {
+				// And its ledger account, `ledger.<node>.<module>` (issue 1966: dropped from the list sealed 2026-11-07 23:09).
+				if user == prefix || strings.HasPrefix(user, prefix+".") || user == "ledger."+prefix {
 					out[user] = fmt.Sprintf("the manifest of %s is %s: %s", module, state, why)
 				}
 			}

modules/mesh-grants/internal/grants/inputs.go

@@ -167,6 +167,9 @@ type Inputs struct {
 	// Refused is every manifest the indexer holds that the part cannot read or mesh-sdk's reader refuses, assigned or
 	// not, each with why: its module counts as placed nowhere, so it is said loudly, never passed over (issue 1945).
 	Refused []Gap
+	// SeatListUnread says the seat list has not been read (the gate says so, seatlist.Reader.MayAct with no seat): only the
+	// bootstrapped seats compose, so the pass keeps what the bus loaded (keeploaded.go).
+	SeatListUnread bool
 	// ByHaves says why this pass placed the modules where the node-engines' haves say they run, the assignments view not
 	// answering (bootstrap only, issue 1966); empty when the assignments placed them. Such a pass retires nothing
 	// (ReadFailures) and seals no list dropping a user of the list in force (holdsBack).
@@ -321,6 +324,7 @@ func ReadInputs(r Reader, cache *Manifests) Inputs {
 	in := Inputs{Assigned: map[string][]string{}, Manifests: map[string]catalogue.Manifest{}, Digests: map[string]string{}, Fingerprints: map[string]string{},
 		NoFingerprint: map[string]string{}, Running: map[string]catalogue.Manifest{},
 		Values: map[string]any{}, Gaps: append([]Gap(nil), standingGaps...)}
+	in.SeatListUnread = gate != nil && !gate.MayAct()
 	nodes := map[string]bool{}
 	// **The seat's assignments alone places modules** (novox/hq ADR 0549 §5, ADR 0567 §9; issue 774): the controller's
 	// assignments are read no more, and the seats held once for the mesh are held where it says. Not read is a failed

modules/mesh-grants/internal/grants/keeploaded.go

@@ -0,0 +1,173 @@
+package grants
+
+import (
+	"encoding/json"
+	"fmt"
+	"slices"
+	"sort"
+)
+
+// **A pass that cannot compose the whole mesh keeps what the bus loaded** (issue 1966, the registry delivery's sealed list of
+// 2026-11-07 23:09). While the seat list is unread (only the bootstrapped seats compose, ADR 0636 §1) or a pass is placed by
+// the node-engines' haves (Inputs.ByHaves), what the composer derives is a part of the mesh: that list sealed took the node
+// seats from every tool runner, the vault's reads from the node-engines and the seat queues from the build modules. Such a
+// pass composes each user of the loaded list and of the list in force as the union of what it composes and what those lists
+// give it (publish, subscribe, the allowance of responses, and every deny any of them says), so it
+// only adds, the indexer's serving of the seat that reads the list included; and the list is held where it would still take
+// a permission from a loaded user (holdsBack, LoadedLosses).
+
+// keepsLoaded says why this pass keeps what the bus loaded, or "" when it composes the whole mesh.
+func (in Inputs) keepsLoaded() string {
+	switch {
+	case in.ByHaves != "":
+		return in.ByHaves
+	case in.SeatListUnread:
+		return "the seat list is unread, so only the bootstrapped seats compose"
+	}
+	return ""
+}
+
+// KeepLoaded is, by user, the union of each user of loaded and of inForce with what composed gives it, for every such user
+// composed gives less than either list (or not at all). Pure.
+func KeepLoaded(composed, loaded []User, inForce map[string]User) map[string]User {
+	byUser := map[string]User{}
+	for _, u := range composed {
+		byUser[u.User] = u
+	}
+	others := map[string][]User{}
+	for _, u := range loaded {
+		others[u.User] = append(others[u.User], u)
+	}
+	for name, u := range inForce {
+		others[name] = append(others[name], u)
+	}
+	out := map[string]User{}
+	for name, from := range others {
+		c, composedHere := byUser[name]
+		short := !composedHere
+		for _, o := range from {
+			if len(Losses(c, o)) > 0 {
+				short = true
+			}
+		}
+		if !short {
+			continue
+		}
+		// Every deny any list says is kept: a deny the composer drops while it composes part of the mesh would widen the
+		// user (the composer gives every composed user a deny, empty or not, so an intersection would drop the list in
+		// force's).
+		u := User{User: name, Publish: c.Publish, Subscribe: c.Subscribe, AllowResponses: c.AllowResponses, PublishDeny: c.PublishDeny}
+		for _, o := range from {
+			u.Publish = set(append(slices.Clone(u.Publish), o.Publish...))
+			u.Subscribe = set(append(slices.Clone(u.Subscribe), o.Subscribe...))
+			u.AllowResponses = u.AllowResponses || o.AllowResponses
+			if o.PublishDeny != nil || u.PublishDeny != nil {
+				u.PublishDeny = set(append(slices.Clone(u.PublishDeny), o.PublishDeny...))
+			}
+		}
+		if u.Publish == nil {
+			u.Publish = []string{}
+		}
+		if u.Subscribe == nil {
+			u.Subscribe = []string{}
+		}
+		out[name] = u
+	}
+	return out
+}
+
+// Losses are how now differs from had where had's word is lost: each publish and subscribe had gives that now does not,
+// the allowance of responses, and, where had's denies are known, each deny now adds and each deny of had now drops (a deny
+// dropped widens the user past what had held it to). Pure.
+func Losses(now, had User) []string {
+	var out []string
+	for _, s := range minus(had.Publish, now.Publish) {
+		out = append(out, "publish "+s)
+	}
+	for _, s := range minus(had.Subscribe, now.Subscribe) {
+		out = append(out, "subscribe "+s)
+	}
+	if had.AllowResponses && !now.AllowResponses {
+		out = append(out, "responses")
+	}
+	if had.PublishDeny != nil {
+		for _, s := range minus(now.PublishDeny, had.PublishDeny) {
+			out = append(out, "deny "+s)
+		}
+		for _, s := range minus(had.PublishDeny, now.PublishDeny) {
+			out = append(out, "deny dropped "+s)
+		}
+	}
+	return out
+}
+
+// LoadedLosses names, sorted, each loaded user the list composed now (listed: its users; composed: their grants) would
+// take a permission from or leave out, with how many it loses. Pure.
+func LoadedLosses(listed []string, composed, loaded []User) []string {
+	byUser := map[string]User{}
+	for _, u := range composed {
+		byUser[u.User] = u
+	}
+	var out []string
+	for _, l := range loaded {
+		c, ok := byUser[l.User]
+		switch {
+		case !slices.Contains(listed, l.User) || !ok:
+			out = append(out, l.User+" (left out)")
+		default:
+			if n := len(Losses(c, l)); n > 0 {
+				out = append(out, fmt.Sprintf("%s (%d permissions)", l.User, n))
+			}
+		}
+	}
+	sort.Strings(out)
+	return slices.Compact(out)
+}
+
+// MembershipNarrows names what the membership last published (was) gives that the one composed now does not, field by field
+// (`<field> <value>`), the private network, the contributions received and the bindings aside, which the pass carries over
+// or the bus module writes; none when now covers was. Both are memberships as JSON. Pure.
+func MembershipNarrows(was, now []byte) []string {
+	var a, b map[string]any
+	if json.Unmarshal(was, &a) != nil || json.Unmarshal(now, &b) != nil {
+		return nil
+	}
+	var out []string
+	for _, field := range sortedKeys(a) {
+		switch field {
+		case "mesh", "receives", "bindings":
+			continue
+		}
+		out = append(out, uncovered(field, a[field], b[field])...)
+	}
+	return out
+}
+
+// uncovered names each part of a that b does not hold: a key of an object by key, an element of a list by its value.
+func uncovered(path string, a, b any) []string {
+	switch av := a.(type) {
+	case map[string]any:
+		bv, _ := b.(map[string]any)
+		var out []string
+		for _, k := range sortedKeys(av) {
+			out = append(out, uncovered(path+"."+k, av[k], bv[k])...)
+		}
+		return out
+	case []any:
+		bv, _ := b.([]any)
+		var out []string
+		for _, e := range av {
+			ej, _ := json.Marshal(e)
+			if !slices.ContainsFunc(bv, func(x any) bool { xj, _ := json.Marshal(x); return string(xj) == string(ej) }) {
+				out = append(out, path+" "+string(ej))
+			}
+		}
+		return out
+	}
+	aj, _ := json.Marshal(a)
+	bj, _ := json.Marshal(b)
+	if string(aj) != string(bj) {
+		return []string{path + " " + string(aj)}
+	}
+	return nil
+}

modules/mesh-grants/internal/grants/part.go

@@ -8,6 +8,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"git.novox.be/novox/mesh-contracts/go/seats/meshbroker"
+	"slices"
 	"sort"
 	"strings"
 	"sync"
@@ -105,7 +106,10 @@ type Result struct {
 	Memberships        int           `json:"memberships"`
 	MembershipsWritten int           `json:"memberships_written"`
 	Published          []string      `json:"published,omitempty"`
-	NotPublished       []string      `json:"not_published,omitempty"`
+	// KeptLoaded are the users a pass composing part of the mesh gave the union of what it composes and what the loaded list
+	// and the list in force give them (keeploaded.go, issue 1966), read with grants_user_list's last pass.
+	KeptLoaded   []string `json:"kept_loaded,omitempty"`
+	NotPublished []string `json:"not_published,omitempty"`
 	// Retired is, by `<node>.<module>`, the seat verbs its last published membership served that mesh-sdk's seat
 	// catalogue no longer has (Membership.Retired): the pass keeps it, since the state memberships holds the bare
 	// membership alone (issue 774).
@@ -331,7 +335,27 @@ func (p *Part) Compose() Result {
 	}
 	p.sayPrincipalsRefused(refused, kept)
 	p.sayHeldModules(heldUsers, kept)
-	users = WithHashes(withKept(users, kept), in.Hashes)
+	users = withKept(users, kept)
+	// A pass that composes part of the mesh keeps what the bus loaded and the list in force give each user (keeploaded.go).
+	if why := in.keepsLoaded(); why != "" {
+		if union := KeepLoaded(users, loaded, inForce); len(union) > 0 {
+			merged := make(map[string]string, len(allRefused)+len(union))
+			keptAll := make(map[string]User, len(kept)+len(union))
+			for u, w := range allRefused {
+				merged[u] = w
+			}
+			for u, k := range kept {
+				keptAll[u] = k
+			}
+			for u, k := range union {
+				merged[u], keptAll[u] = "keeps what the loaded list gives it: "+why, k
+			}
+			users = withKept(slices.DeleteFunc(users, func(u User) bool { _, ok := union[u.User]; return ok }), union)
+			allRefused, kept = merged, keptAll
+			res.KeptLoaded = sortedKeys(union)
+		}
+	}
+	users = WithHashes(users, in.Hashes)
 	st.Digest, st.Users = Digest(users), len(users)
 	st.Compare = Compare(users, loaded, Placed(in)).Excusing(ExcusedBy(MultiHeld(listRecs)))
 	if loadErr != nil {
@@ -381,7 +405,7 @@ func (p *Part) Compose() Result {
 			bus = names(loaded)
 			lost = holdings.LastHolders(holdings.ByUsers(loaded), holdings.ByUsers(users))
 		}
-		p.writeSealed(&res, list, n, leftOut, dropped, in, bus, lost, users)
+		p.writeSealed(&res, list, n, leftOut, dropped, in, bus, lost, users, loaded)
 	}
 	ms := Memberships(recs)
 	res.Memberships = len(ms)
@@ -410,6 +434,17 @@ func (p *Part) Compose() Result {
 			continue
 		}
 		m, now := publish(was, found, ms[key], holdings, seated)
+		// A pass that composes part of the mesh never narrows a published membership: it keeps the one published
+		// (keeploaded.go, issue 1966), so a tool runner or a seat holder goes on serving what it serves.
+		if why := in.keepsLoaded(); now && found && why != "" {
+			if body, err := json.Marshal(m.Membership); err == nil {
+				if bare, err := membership.BareGrantsMembership(was); err == nil {
+					if narrower := MembershipNarrows(bare, body); len(narrower) > 0 {
+						m.Published, now = "kept as published: "+why+", and this pass composes it without "+strings.Join(narrower, ", "), false
+					}
+				}
+			}
+		}
 		// Published is written to the state, where every runtime reads it (process.FollowMembership); only one
 		// published, so a membership held back never reaches a reader.
 		if now {

modules/mesh-grants/internal/grants/sealed.go

@@ -83,7 +83,7 @@ func (p *Part) Sealed() (grantsstate.GrantsUserList, uint64, bool) {
 
 // writeSealed puts the list sealed to the bus node and writes the key, each only when what it says changed. It says in
 // res what it wrote, or why it wrote nothing.
-func (p *Part) writeSealed(res *Result, list []byte, users int, leftOut, dropped []string, in Inputs, bus []string, lost []string, composed []User) {
+func (p *Part) writeSealed(res *Result, list []byte, users int, leftOut, dropped []string, in Inputs, bus []string, lost []string, composed, loaded []User) {
 	cur, _, had := p.Sealed()
 	next := cur
 	// The bus node follows this list alone (ADR 0571 clause 8): always since the controller ended by its unassignment
@@ -104,10 +104,10 @@ func (p *Part) writeSealed(res *Result, list []byte, users int, leftOut, dropped
 		why = "no node runs the bus's module, so the list is sealed to nobody"
 	case key == "":
 		why = "the bus node's have of the bus module names no key yet (its node-engine says it from this release)"
-	case cur.Digest != digest && p.holdsBack(in, leftOut, dropped, bus, lost, listUsers(list), digest) != "":
+	case cur.Digest != digest && p.holdsBack(in, leftOut, dropped, bus, lost, listUsers(list), composed, loaded, digest) != "":
 		// The list in force is never replaced by one composed past a failed read, or one that drops a user of it for want
 		// of a hash: that user's module would be locked out of the bus (review of the switch).
-		why = p.holdsBack(in, leftOut, dropped, bus, lost, listUsers(list), digest)
+		why = p.holdsBack(in, leftOut, dropped, bus, lost, listUsers(list), composed, loaded, digest)
 		held = why
 		p.keepHashHold(res, digest)
 	case cur.Digest != digest || cur.SealedTo != grantsstate.SealingKeyID(key) || cur.Node != in.BusNode:
@@ -299,10 +299,10 @@ func listUsers(list []byte) []string {
 // it kept of it; where it kept none (a list written before this release), the users the bus loaded (bus, nil when
 // they could not be read). Empty when it may.
 //
-// In a pass placed by the node-engines' haves (in.ByHaves, issue 1966) the list is held, too, while it would leave out any user
-// of the list in force or of the list the bus loaded (listed are the users of the list composed now): a bootstrap placement
-// adds logins and never takes one away.
-func (p *Part) holdsBack(in Inputs, leftOut, dropped, bus, lost, listed []string, digest string) string {
+// In a pass that composes part of the mesh (placed by the node-engines' haves, or the seat list unread; keeploaded.go, issue
+// 1966) the list is held, too, while it would leave out any user of the list in force or take any permission from a user of
+// the list the bus loaded (listed are the users of the list composed now, composed their grants): such a pass only adds.
+func (p *Part) holdsBack(in Inputs, leftOut, dropped, bus, lost, listed []string, composed, loaded []User, digest string) string {
 	p.hashHold = nil
 	if f := in.ReadFailed(); len(f) > 0 {
 		return "held: the list in force is kept while a read of this pass failed (" + strings.Join(f, "; ") + ")"
@@ -324,7 +324,10 @@ func (p *Part) holdsBack(in Inputs, leftOut, dropped, bus, lost, listed []string
 	default:
 		had = bus
 	}
-	if in.ByHaves != "" {
+	if why := in.keepsLoaded(); why != "" {
+		if losses := LoadedLosses(listed, composed, loaded); len(losses) > 0 {
+			return "held: " + why + ", and the list composed so would take from loaded users: " + strings.Join(losses, ", ")
+		}
 		var gone []string
 		for _, u := range append(slices.Clone(had), bus...) {
 			if !slices.Contains(listed, u) && !slices.Contains(gone, u) {
@@ -333,7 +336,7 @@ func (p *Part) holdsBack(in Inputs, leftOut, dropped, bus, lost, listed []string
 		}
 		if len(gone) > 0 {
 			slices.Sort(gone)
-			return "held: " + in.ByHaves + ", and the list composed so would drop " + strings.Join(gone, ", ") + " of the list in force"
+			return "held: " + why + ", and the list composed so would drop " + strings.Join(gone, ", ") + " of the list in force"
 		}
 	}
 	var unhashed []string