fix(stalker): reject replaced late edit targets

libs/playlist/shared/ui/src/lib/recent-playlists/playlist-info/playlist-info.component.spec.ts

@@ -669,6 +669,10 @@ describe('PlaylistInfoComponent', () => {
                     stalkerDeviceId2: 'STORED-DEVICE-2',
                     stalkerSignature1: 'STORED-SIGNATURE-1',
                     stalkerSignature2: 'STORED-SIGNATURE-2',
+                }),
+                expect.objectContaining({
+                    portalUrl: 'https://portal.example.com/c',
+                    stalkerSerialNumber: 'STORED-SERIAL',
                 })
             );
         });

libs/playlist/shared/ui/src/lib/recent-playlists/playlist-info/playlist-info.component.ts

@@ -413,7 +413,8 @@ export class PlaylistInfoComponent {
                 ) {
                     const result =
                         await this.stalkerConnectionEditor.resolveConnection(
-                            normalizedPlaylist
+                            normalizedPlaylist,
+                            this.playlist
                         );
                     if (
                         result.status !==

libs/playlist/shared/ui/src/lib/recent-playlists/playlist-info/stalker-playlist-connection-editor.token.ts

@@ -41,7 +41,8 @@ export interface StalkerResolvedConnectionApplyOptions {
 
 export interface StalkerPlaylistConnectionEditor {
     resolveConnection(
-        playlist: PlaylistMeta
+        playlist: PlaylistMeta,
+        sourcePlaylist?: PlaylistMeta
     ): Promise<StalkerPlaylistConnectionResult>;
     /** Atomically persists a resolved edit, then synchronizes in-run state. */
     applyResolvedConnection(

libs/portal/stalker/data-access/src/lib/stalker-edited-session-coordinator.spec.ts

@@ -341,7 +341,10 @@ describe('Stalker edited-session coordination', () => {
             stalkerWatchdogTimeout: 90,
             stalkerTimeslot: 5,
         } as Playlist;
-        const fence = await service.beginEditDiscovery(editedPlaylist);
+        const fence = await service.beginEditDiscovery(
+            editedPlaylist,
+            oldPlaylist
+        );
 
         const persisted = await service.replaceSessionAfterEdit(
             editedPlaylist,
@@ -367,6 +370,35 @@ describe('Stalker edited-session coordination', () => {
         );
     });
 
+    it('rejects a late merge after another connection replaces the playlist ID', async () => {
+        const replacementPlaylist = {
+            ...oldPlaylist,
+            portalUrl: 'https://restored.example.com/portal.php',
+            macAddress: '00:1A:79:11:22:33',
+        } as Playlist;
+        transformPlaylistMeta.mockImplementationOnce((_id, transform) =>
+            of(transform(replacementPlaylist))
+        );
+        const editedPlaylist = {
+            ...oldPlaylist,
+            portalUrl: 'https://new.example.com/server/load.php',
+            stalkerToken: 'NEW_TOKEN',
+        } as Playlist;
+        const fence = await service.beginEditDiscovery(
+            editedPlaylist,
+            oldPlaylist
+        );
+
+        await expect(
+            service.replaceSessionAfterEdit(editedPlaylist, fence, {
+                preserveCurrentMetadata: true,
+            })
+        ).rejects.toThrow(/could not be persisted/i);
+
+        expect(service.getCachedToken(oldPlaylist._id)).toBeNull();
+        expect(updatePlaylistMeta).not.toHaveBeenCalled();
+    });
+
     it('does not adopt a resolved full session when its atomic write fails', async () => {
         service.adoptDiscoveredSimplePortal(oldPlaylist);
         updatePlaylistMeta.mockReturnValueOnce(

libs/portal/stalker/data-access/src/lib/stalker-edited-session-coordinator.ts

@@ -18,6 +18,7 @@ export interface StalkerEditFence {
 interface PendingEdit {
     readonly owner: symbol;
     readonly configurationFingerprint: string;
+    readonly sourceConfigurationFingerprint: string;
 }
 
 /** Serializes authoritative Edit results against pre-edit authentication. */
@@ -87,8 +88,14 @@ export class StalkerEditedSessionCoordinator {
         }
     }
 
-    async beginEdit(playlist: Playlist): Promise<StalkerEditFence> {
+    async beginEdit(
+        playlist: Playlist,
+        sourcePlaylist: Playlist = playlist
+    ): Promise<StalkerEditFence> {
         const playlistId = playlist._id;
+        if (sourcePlaylist._id !== playlistId) {
+            throw new Error('Stale Stalker playlist configuration');
+        }
         if (this.pendingEdits.has(playlistId)) {
             throw new Error('Stalker playlist edit already in progress');
         }
@@ -98,6 +105,8 @@ export class StalkerEditedSessionCoordinator {
         this.pendingEdits.set(playlistId, {
             owner: fence.owner,
             configurationFingerprint,
+            sourceConfigurationFingerprint:
+                stalkerConfigurationFingerprint(sourcePlaylist),
         });
 
         try {
@@ -132,6 +141,7 @@ export class StalkerEditedSessionCoordinator {
             sessionFingerprint
         );
         const owner = fence?.owner ?? Symbol('stalker-edit');
+        const pending = this.pendingEdits.get(playlistId);
         if (
             fence &&
             (fence.playlistId !== playlistId ||
@@ -141,11 +151,15 @@ export class StalkerEditedSessionCoordinator {
                 new Error('Stale Stalker playlist configuration')
             );
         }
+        const sourceConfigurationFingerprint =
+            pending?.sourceConfigurationFingerprint ??
+            stalkerConfigurationFingerprint(playlist);
         // Keep the same owner while discovery replaces its input-shaped
         // fingerprint with the resolved endpoint/mode fingerprint.
         this.pendingEdits.set(playlistId, {
             owner,
             configurationFingerprint,
+            sourceConfigurationFingerprint,
         });
         const previous = this.replacements.get(playlistId) ?? Promise.resolve();
         const replacement = previous
@@ -156,6 +170,7 @@ export class StalkerEditedSessionCoordinator {
                     sessionFingerprint,
                     configurationFingerprint,
                     owner,
+                    sourceConfigurationFingerprint,
                     options
                 )
             );
@@ -178,6 +193,7 @@ export class StalkerEditedSessionCoordinator {
         sessionFingerprint: string,
         configurationFingerprint: string,
         owner: symbol,
+        sourceConfigurationFingerprint: string,
         options: { preserveCurrentMetadata?: boolean }
     ): Promise<Playlist> {
         const playlistId = playlist._id;
@@ -215,11 +231,14 @@ export class StalkerEditedSessionCoordinator {
         const persistedPlaylist = await firstValueFrom(
             options.preserveCurrentMetadata
                 ? playlists.transformPlaylistMeta(playlistId, (current) =>
-                      mergeResolvedStalkerConnection(
-                          current,
-                          playlist,
-                          sessionPatch
-                      )
+                      stalkerConfigurationFingerprint(current) ===
+                      sourceConfigurationFingerprint
+                          ? mergeResolvedStalkerConnection(
+                                current,
+                                playlist,
+                                sessionPatch
+                            )
+                          : null
                   )
                 : playlists.updatePlaylistMeta({
                       ...playlist,

libs/portal/stalker/data-access/src/lib/stalker-session.service.ts

@@ -253,8 +253,11 @@ export class StalkerSessionService {
      * before discovery. The opaque fence keeps new authentication out until
      * the result is either cancelled or atomically persisted.
      */
-    beginEditDiscovery(playlist: Playlist): Promise<StalkerEditFence> {
-        return this.editedSessions.beginEdit(playlist);
+    beginEditDiscovery(
+        playlist: Playlist,
+        sourcePlaylist: Playlist = playlist
+    ): Promise<StalkerEditFence> {
+        return this.editedSessions.beginEdit(playlist, sourcePlaylist);
     }
 
     /**