fix(maps): stop delivering settled state to detached subscribers

CHANGELOG.md

@@ -32,6 +32,7 @@
 - Tool string length validation counts Unicode characters correctly, including characters outside the basic multilingual plane.
 
 - Director timeline seeks cross the dateline along the short longitude arc.
+- Map state updates stop delivering to subscribers removed during the same notification.
 
 - Treat explicitly current, complete empty vessel coverage as a successful update,
   clearing obsolete contacts while retaining stale or incomplete snapshots.

docs/CURRENT-STATE.md

@@ -5326,3 +5326,8 @@ datacenters, dams and the Nepal locator retain that shared credit while displaye
 
 Military fragments stitch by source identity. Different mapped parcels merge only
 when their footprints touch or contain one another, never across a seam tolerance gap.
+
+
+### fix(maps): stop delivering settled state to detached subscribers
+
+Recheck listener ownership and controller lifetime before each settled-state callback. Still-active subscribers keep their ordering and exception isolation.

src/maps/controller.js

@@ -142,6 +142,7 @@ export class MapSourceController {
     if (this._destroyed || !this._subscribers.size) return;
     const state = this.getState();
     for (const listener of [...this._subscribers]) {
+      if (this._destroyed || !this._subscribers.has(listener)) continue;
       try {
         listener(state);
       } catch (error) {

src/maps/map-subscription-ownership.test.mjs

@@ -0,0 +1,55 @@
+import test from 'node:test';
+import assert from 'node:assert/strict';
+import { MapSourceController } from './controller.js';
+function fixture() {
+  return new MapSourceController(
+    {
+      scene: {
+        globe: { show: true },
+        requestRender() {},
+        frameState: {
+          creditDisplay: { addStaticCredit() {}, removeStaticCredit() {} },
+        },
+        primitives: { add() {}, remove() {} },
+      },
+      imageryLayers: { add() {}, remove() {} },
+    },
+    {
+      registry: {
+        defaultId: 'fixture',
+        sources: [
+          {
+            descriptor: { id: 'fixture', label: 'Fixture', kind: 'imagery' },
+            imagery: async () => ({}),
+          },
+        ],
+      },
+      createImageryLayer: (provider) => ({ provider }),
+    },
+  );
+}
+test('an unsubscribed owner is skipped in the same map settlement delivery', async () => {
+  const controller = fixture();
+  const calls = [];
+  let detach;
+  controller.subscribe(() => {
+    calls.push('first');
+    detach();
+  });
+  detach = controller.subscribe(() => calls.push('detached'));
+  controller.subscribe(() => calls.push('last'));
+  await controller.setStack('fixture');
+  assert.deepEqual(calls, ['first', 'last']);
+  controller.destroy();
+});
+test('destroying the controller during delivery stops remaining listeners', async () => {
+  const controller = fixture();
+  const calls = [];
+  controller.subscribe(() => {
+    calls.push('destroy');
+    controller.destroy();
+  });
+  controller.subscribe(() => calls.push('detached'));
+  await controller.setStack('fixture');
+  assert.deepEqual(calls, ['destroy']);
+});