Fix addon settings reset live reload

src/addons/settings-store.js

@@ -320,7 +320,8 @@ class SettingsStore extends EventTargetShim {
                 const manifest = this.getAddonManifest(addonId);
                 const dynamicEnable = !!manifest.dynamicEnable && !oldSettings.enabled && newSettings.enabled;
                 const dynamicDisable = !!manifest.dynamicDisable && oldSettings.enabled && !newSettings.enabled;
-                Object.assign(oldSettings, newSettings);
+                // Clone to avoid pass-by-reference issues
+                this.store[addonId] = JSON.parse(JSON.stringify(newSettings));
                 this.dispatchEvent(new CustomEvent('addon-changed', {
                     detail: {
                         addonId,

test/unit/addons/settings.test.js

@@ -429,3 +429,13 @@ test('setStore weird values', () => {
     });
     expect(settingsStore.getAddonEnabled('pause')).toBe(false);
 });
+
+test('resetting an addon through setStore', () => {
+    const store = new SettingStore();
+    expect(store.getAddonSetting('custom-block-shape', 'paddingSize')).toBe(100);
+    store.setAddonSetting('custom-block-shape', 'paddingSize', 50);
+    expect(store.getAddonSetting('custom-block-shape', 'paddingSize')).toBe(50);
+    const store2 = new SettingStore();
+    store.setStore(store2.store);
+    expect(store.getAddonSetting('custom-block-shape', 'paddingSize')).toBe(100);
+});