fix: prune orphaned static actor vid conflicts

Author: MikelCalvo

internal/worldruntime/non_player_directory.go

@@ -22,7 +22,7 @@ func (d *NonPlayerDirectory) Register(actor StaticEntity) bool {
 	if _, ok := d.byEntityID[actor.Entity.ID]; ok {
 		return false
 	}
-	if vid, ok := StaticActorVisibilityVID(actor); ok && conflictingEntityID(d.entityIDByVID, vid, actor.Entity.ID) {
+	if vid, ok := StaticActorVisibilityVID(actor); ok && d.conflictingVisibilityVID(vid, actor.Entity.ID) {
 		return false
 	}
 	d.removeVisibilityVIDsForEntityID(actor.Entity.ID)
@@ -65,7 +65,7 @@ func (d *NonPlayerDirectory) Update(actor StaticEntity) bool {
 	if _, ok := d.byEntityID[actor.Entity.ID]; !ok {
 		return false
 	}
-	if vid, ok := StaticActorVisibilityVID(actor); ok && conflictingEntityID(d.entityIDByVID, vid, actor.Entity.ID) {
+	if vid, ok := StaticActorVisibilityVID(actor); ok && d.conflictingVisibilityVID(vid, actor.Entity.ID) {
 		return false
 	}
 	d.removeVisibilityVIDsForEntityID(actor.Entity.ID)
@@ -100,6 +100,18 @@ func (d *NonPlayerDirectory) removeVisibilityVIDsForEntityID(entityID uint64) {
 	}
 }
 
+func (d *NonPlayerDirectory) conflictingVisibilityVID(vid uint32, entityID uint64) bool {
+	indexedEntityID, ok := d.entityIDByVID[vid]
+	if !ok || indexedEntityID == entityID {
+		return false
+	}
+	if _, exists := d.byEntityID[indexedEntityID]; exists {
+		return true
+	}
+	delete(d.entityIDByVID, vid)
+	return false
+}
+
 func (d *NonPlayerDirectory) StaticActors() []StaticEntity {
 	if d == nil || len(d.byEntityID) == 0 {
 		return nil

internal/worldruntime/non_player_directory_test.go

@@ -80,6 +80,47 @@ func TestNonPlayerDirectoryLookupPrunesStaleVisibilityVID(t *testing.T) {
 	}
 }
 
+func TestNonPlayerDirectoryRegisterPrunesOrphanedVisibilityVIDConflict(t *testing.T) {
+	directory := NewNonPlayerDirectory()
+	directory.entityIDByVID[7] = 999
+
+	actor := StaticEntity{
+		Entity:   Entity{ID: 7, Kind: EntityKindStaticActor, Name: "VillageGuard"},
+		Position: NewPosition(42, 1700, 2800),
+		RaceNum:  20300,
+	}
+	if !directory.Register(actor) {
+		t.Fatal("expected static actor registration to prune orphaned VID conflict")
+	}
+	lookup, ok := directory.ByVID(7)
+	if !ok || lookup.Entity.ID != actor.Entity.ID || lookup.Entity.Name != actor.Entity.Name {
+		t.Fatalf("expected current visibility VID lookup after orphan prune, got actor=%+v ok=%v", lookup, ok)
+	}
+}
+
+func TestNonPlayerDirectoryUpdatePrunesOrphanedVisibilityVIDConflict(t *testing.T) {
+	directory := NewNonPlayerDirectory()
+	actor := StaticEntity{
+		Entity:   Entity{ID: 7, Kind: EntityKindStaticActor, Name: "VillageGuard"},
+		Position: NewPosition(42, 1700, 2800),
+		RaceNum:  uint32(^uint16(0)) + 1,
+	}
+	if !directory.Register(actor) {
+		t.Fatal("expected non-encodable static actor registration to succeed")
+	}
+	directory.entityIDByVID[7] = 999
+
+	updated := actor
+	updated.RaceNum = 20300
+	if !directory.Update(updated) {
+		t.Fatal("expected static actor update to prune orphaned VID conflict")
+	}
+	lookup, ok := directory.ByVID(7)
+	if !ok || lookup.Entity.ID != actor.Entity.ID || lookup.RaceNum != 20300 {
+		t.Fatalf("expected current visibility VID lookup after update orphan prune, got actor=%+v ok=%v", lookup, ok)
+	}
+}
+
 func TestNonPlayerDirectoryUpdateReplacesStaticActorByEntityID(t *testing.T) {
 	directory := NewNonPlayerDirectory()
 	actor := StaticEntity{

spec/protocol/non-player-entity-bootstrap.md

@@ -102,6 +102,7 @@ This slice does not yet freeze:
   - if a bad partial-teardown or repair path leaves duplicate map-bucket presence for the same static actor entity ID, later register, in-place update, or remove must prune all stale map buckets before inserting the new effective-map presence or reporting final removal; map occupancy must never keep ghost static actors for the same entity ID on older maps
   - if a stale visibility-VID index entry survives for the same static actor entity ID, later registration or in-place update must prune the stale VID before inserting the actor's current encodable visibility VID; removal must prune every visibility VID alias for the removed entity ID; visible-VID lookup must never keep an old alias for the same static actor after registration, update repair, or removal
   - if a stale visibility-VID index entry points at a missing static actor entity ID, a later `ByVID` lookup must prune that orphaned index entry before failing closed; visible-VID lookup must not keep returning through stale non-player directory aliases after partial teardown
+  - if that orphaned visibility-VID entry would otherwise conflict with later registration or in-place update of the real actor for that VID, the non-player directory must prune the orphan and allow the current actor to claim the VID; only live conflicting actor ownership should fail closed
 - inter-channel ownership
 
 ## Success definition for the next slice