From 2acec49b29dbc0768d02a52f10e64dfe8b435729 Mon Sep 17 00:00:00 2001
From: Dermot Duffy <dermot.duffy@gmail.com>
Date: Tue, 19 May 2026 22:05:59 -0700
Subject: [PATCH] refactor: Clone context when a view is cloned (#2493)

---
 src/card-controller/call/manager.ts |  7 ++-----
 src/components/viewer/carousel.ts   |  6 ++++--
 src/view/view.ts                    |  6 +++---
 tests/view/view.test.ts             | 21 ++++++++++++++++++++-
 4 files changed, 29 insertions(+), 11 deletions(-)

diff --git a/src/card-controller/call/manager.ts b/src/card-controller/call/manager.ts
index 545ff1e1..bbe0cc6e 100644
--- a/src/card-controller/call/manager.ts
+++ b/src/card-controller/call/manager.ts
@@ -1,4 +1,3 @@
-import { cloneDeep } from 'lodash-es';
 import { createNotificationFromText } from '../../components-lib/notification/factory';
 import { ConditionStateChange } from '../../conditions/types';
 import { localize } from '../../localize/localize';
@@ -88,12 +87,10 @@ export class CallManager {
 
     // Store the previous view so it can be restored later. A call superseding
     // another inherits the earlier call's previous view -- the user never left
-    // the call. `queryResults` are dropped (re-fetched fresh on restore);
-    // `context` is deep-cloned so the call engaging its own substream below
-    // cannot mutate the snapshot.
+    // the call. `queryResults` are dropped (re-fetched fresh on restore).
     const previousView = existingCall
       ? existingCall.previousView
-      : view.evolve({ queryResults: null, context: cloneDeep(view.context) });
+      : view.evolve({ queryResults: null });
 
     const needsNavigation = !view.is('live') || view.camera !== parentID;
 
diff --git a/src/components/viewer/carousel.ts b/src/components/viewer/carousel.ts
index ed6a9085..94fa65e0 100644
--- a/src/components/viewer/carousel.ts
+++ b/src/components/viewer/carousel.ts
@@ -383,8 +383,10 @@ export class AdvancedCameraCardViewerCarousel extends LitElement {
       // on media load, since the media may or may not have been loaded at
       // this point).
       if (
-        this.viewManagerEpoch?.manager.getView()?.context?.mediaViewer !==
-        this.viewManagerEpoch?.oldView?.context?.mediaViewer
+        this.viewManagerEpoch?.manager
+          .getView()
+          ?.context?.mediaViewer?.seek?.getTime() !==
+        this.viewManagerEpoch?.oldView?.context?.mediaViewer?.seek?.getTime()
       ) {
         this._seekHandler();
       }
diff --git a/src/view/view.ts b/src/view/view.ts
index cf200973..e1dc0fa0 100644
--- a/src/view/view.ts
+++ b/src/view/view.ts
@@ -1,4 +1,4 @@
-import { merge } from 'lodash-es';
+import { cloneDeep, merge } from 'lodash-es';
 import { ViewContext } from 'view';
 import { AdvancedCameraCardView } from '../config/schema/common/const';
 import { ViewDisplayMode } from '../config/schema/common/display';
@@ -95,7 +95,7 @@ export class View {
       camera: this.camera,
       query: this.query?.clone() ?? null,
       queryResults: this.queryResults?.clone() ?? null,
-      context: this.context,
+      context: cloneDeep(this.context),
       displayMode: this.displayMode,
     });
   }
@@ -114,7 +114,7 @@ export class View {
         params.queryResults !== undefined
           ? params.queryResults
           : this.queryResults?.clone() ?? null,
-      context: params.context !== undefined ? params.context : this.context,
+      context: params.context !== undefined ? params.context : cloneDeep(this.context),
       displayMode:
         params.displayMode !== undefined ? params.displayMode : this.displayMode,
     });
diff --git a/tests/view/view.test.ts b/tests/view/view.test.ts
index 6c88a4a7..3f6c4808 100644
--- a/tests/view/view.test.ts
+++ b/tests/view/view.test.ts
@@ -87,7 +87,10 @@ describe('View Basics', () => {
 
     expect(evolved.view).toBe(view.view);
     expect(evolved.camera).toBe(view.camera);
-    expect(evolved.context).toBe(view.context);
+
+    // Context is deep-cloned if not set, so the evolved view owns it.
+    expect(evolved.context).not.toBe(view.context);
+    expect(evolved.context).toEqual(view.context);
 
     // Query and QueryResults are cloned if not set.
     expect(evolved.query).not.toBe(view.query);
@@ -96,6 +99,22 @@ describe('View Basics', () => {
     expect(evolved.queryResults).toEqual(view.queryResults);
   });
 
+  it('should isolate inherited context from mutation on clone and evolve', () => {
+    const view = createView({
+      view: 'live',
+      camera: 'camera-1',
+      context: { live: { overrides: new Map([['camera-1', 'sub-1']]) } },
+    });
+
+    const cloned = view.clone();
+    const evolved = view.evolve({});
+
+    cloned.context?.live?.overrides?.set('camera-1', 'mutated-clone');
+    evolved.context?.live?.overrides?.delete('camera-1');
+
+    expect(view.context?.live?.overrides?.get('camera-1')).toBe('sub-1');
+  });
+
   it('should not clone query and queryResults with nothing set', () => {
     const view = createView();
     const evolved = view.evolve({});