Fix issue where block inserted in wrong place when selection is in ne…

…sted block list, but root appender is used. (#23668)

* Remove use of getSelectionEnd to determine where blocks should be inserted

* Add e2e tests

packages/block-editor/src/components/inserter/index.js

@@ -183,14 +183,11 @@ export default compose( [
 			getBlockRootClientId,
 			hasInserterItems,
 			__experimentalGetAllowedBlocks,
-			getBlockSelectionEnd,
 		} = select( 'core/block-editor' );
 		const { getBlockVariations } = select( 'core/blocks' );
 
 		rootClientId =
-			rootClientId ||
-			getBlockRootClientId( clientId || getBlockSelectionEnd() ) ||
-			undefined;
+			rootClientId || getBlockRootClientId( clientId ) || undefined;
 
 		const allowedBlocks = __experimentalGetAllowedBlocks( rootClientId );
 

packages/e2e-tests/specs/editor/various/__snapshots__/adding-blocks.test.js.snap

@@ -52,3 +52,15 @@ Foo</pre>
 lines preserved[/myshortcode]
 <!-- /wp:shortcode -->"
 `;
+
+exports[`adding blocks inserts blocks at root level when using the root appender while selection is in an inner block 1`] = `
+"<!-- wp:buttons -->
+<div class=\\"wp-block-buttons\\"><!-- wp:button -->
+<div class=\\"wp-block-button\\"><a class=\\"wp-block-button__link\\">1.1</a></div>
+<!-- /wp:button --></div>
+<!-- /wp:buttons -->
+
+<!-- wp:paragraph -->
+<p>2</p>
+<!-- /wp:paragraph -->"
+`;

packages/e2e-tests/specs/editor/various/adding-blocks.test.js

@@ -190,4 +190,31 @@ describe( 'adding blocks', () => {
 			'block-editor-inserter__toggle'
 		);
 	} );
+
+	// Check for regression of https://github.com/WordPress/gutenberg/issues/23263
+	it( 'inserts blocks at root level when using the root appender while selection is in an inner block', async () => {
+		await insertBlock( 'Buttons' );
+		await page.keyboard.type( '1.1' );
+
+		// After inserting the Buttons block the inner button block should be selected.
+		const selectedButtonBlocks = await page.$$(
+			'.wp-block-button.is-selected'
+		);
+		expect( selectedButtonBlocks.length ).toBe( 1 );
+
+		// Specifically click the root container appender.
+		await page.click(
+			'.block-editor-block-list__layout.is-root-container > .block-list-appender .block-editor-inserter__toggle'
+		);
+
+		// Insert a paragraph block.
+		await page.waitForSelector( '.block-editor-inserter__search-input' );
+		await page.keyboard.type( 'Paragraph' );
+		await page.click( '.editor-block-list-item-paragraph' );
+		await page.keyboard.type( '2' );
+
+		// The snapshot should show a buttons block followed by a paragraph.
+		// The buttons block should contain a single button.
+		expect( await getEditedPostContent() ).toMatchSnapshot();
+	} );
 } );