Editor: Keep a preview canvas from adopting the entity's selection

packages/editor/CHANGELOG.md

@@ -20,6 +20,7 @@
 -   `PostPanelRow`: Wrap long unbroken values (such as an author name or email) inside the row instead of overflowing the Post sidebar ([#84165](https://github.com/WordPress/gutenberg/pull/84165)).
 -   Visual History: Render the inline removed-text diff (`<del>`) at the theme's body color over a red-tinted background instead of recoloring it with a translucent color-matrix filter, so it keeps the theme's WCAG AA contrast on any background ([#82258](https://github.com/WordPress/gutenberg/pull/82258)).
 -   Notes: Stop announcing the "Add note" block menu item as opening a dialog ([#84818](https://github.com/WordPress/gutenberg/pull/84818)).
+-   `EditorProvider`: Keep a preview canvas from restoring a block selection written to the entity by another editor, such as the site editor's navigation sidebar ([#84832](https://github.com/WordPress/gutenberg/pull/84832)).
 
 ### Internal
 

packages/editor/src/components/provider/index.jsx

@@ -424,6 +424,10 @@ export const ExperimentalEditorProvider = withRegistryProvider(
 			return null;
 		}
 
+		// Selections should not be synced when in revision or preview modes.
+		const shouldSyncSelection =
+			! isInRevisionsMode && ! settings.isPreviewMode;
+
 		return (
 			<EntityProvider kind="root" type="site">
 				<EntityProvider
@@ -438,10 +442,10 @@ export const ExperimentalEditorProvider = withRegistryProvider(
 							onChange={ onChange }
 							onInput={ onInput }
 							selection={
-								isInRevisionsMode ? undefined : selection
+								shouldSyncSelection ? selection : undefined
 							}
 							onChangeSelection={
-								isInRevisionsMode ? noop : onChangeSelection
+								shouldSyncSelection ? onChangeSelection : noop
 							}
 							settings={ blockEditorSettings }
 							useSubRegistry={ false }

test/e2e/specs/site-editor/navigation-sidebar-list-view.spec.js

@@ -147,6 +147,51 @@ test.describe( 'Navigation sidebar - list view editing', () => {
 			).toBeVisible();
 		} );
 	} );
+
+	test( 'does not select blocks in the canvas preview when editing from the sidebar', async ( {
+		admin,
+		page,
+		requestUtils,
+		linkControl,
+	} ) => {
+		const createdMenu =
+			await requestUtils.createNavigationMenu( navMenuFixture );
+
+		await admin.visitSiteEditor( {
+			postId: createdMenu?.id,
+			postType: 'wp_navigation',
+		} );
+
+		const listView = page.getByRole( 'treegrid', {
+			name: 'Block navigation structure',
+		} );
+		const canvas = page.frameLocator( 'iframe[name="editor-canvas"]' );
+		const blockToolbar = page.getByRole( 'toolbar', {
+			name: 'Block tools',
+		} );
+
+		await expect( canvas.getByText( 'Existing Item' ) ).toBeVisible();
+
+		// Select an item, then add a new one from the appender. The edit is
+		// what carries the sidebar's selection over to the entity.
+		await listView.getByRole( 'link', { name: 'Existing Item' } ).click();
+		await listView.getByRole( 'button', { name: 'Add page' } ).click();
+		await linkControl.useLinkControlSearch( 'Test Page 2' );
+		await expect(
+			listView.getByRole( 'link', { name: 'Test Page 2' } )
+		).toBeVisible();
+
+		// The preview picks up the change without adopting the selection.
+		await expect( canvas.getByText( 'Test Page 2' ) ).toBeVisible();
+		await expect( blockToolbar ).toBeHidden();
+		expect(
+			await page.evaluate( () =>
+				window.wp.data
+					.select( 'core/block-editor' )
+					.getSelectedBlockClientId()
+			)
+		).toBeNull();
+	} );
 } );
 
 class LinkControl {