Block Editor: Bail out of hasSelectedInnerBlock when there is no clientId

packages/block-editor/CHANGELOG.md

@@ -16,6 +16,7 @@
 -   `BlockListBlock`: Skip that deep check behind `isSelectionWithinCurrentSection` when the block is not within a section block, where it was passed an `undefined` client ID that never matches. Together the two changes take selecting all blocks on a 1000 paragraph post from 16.8s to 0.4s ([#81210](https://github.com/WordPress/gutenberg/pull/81210)).
 -   `ListView`: Drop the `useBlockDisplayInformation` and `useBlockLock` calls from the row, select button and branch components, reading the few fields they were used for from the `useSelect` each component already has. Store subscriptions go from seven to four per rendered row, and from two to one per branch ([#81136](https://github.com/WordPress/gutenberg/pull/81136)).
 -   `ListView`: Collapse the placeholder rows that stand in for blocks outside of the render window into a single spacer row per run, instead of rendering a `<tr>`/`<td>` pair for every block. On a post with 1000 top-level blocks this removes ~1900 elements (about 60% of the List View's DOM and nearly half of the document's elements), which cuts the style recalculation and layout work done when the List View opens ([#80953](https://github.com/WordPress/gutenberg/pull/80953)).
+-   `hasSelectedInnerBlock`: Return `false` up front when called without a client ID, instead of reading the selection and walking it for a check that can never match. The root client ID (`''`) is covered by the same bail out, so the shallow check no longer reports `true` when a top level block is selected, matching the deep check ([#81315](https://github.com/WordPress/gutenberg/pull/81315)).
 
 ### Internal
 

packages/block-editor/src/components/block-list/block.js

@@ -686,13 +686,9 @@ function BlockListBlockProvider( props ) {
 			const sectionBlockClientId = isSectionBlock
 				? clientId
 				: getParentSectionBlock( clientId );
-			// Without a section block there is nothing for the deep check to
-			// match, and it walks the parents of every selected block to find
-			// that out.
 			const isSelectionWithinCurrentSection =
 				isBlockSelected( sectionBlockClientId ) ||
-				( !! sectionBlockClientId &&
-					hasSelectedInnerBlock( sectionBlockClientId, checkDeep ) );
+				hasSelectedInnerBlock( sectionBlockClientId, checkDeep );
 
 			const multiple = hasBlockSupport( blockName, 'multiple', true );
 

packages/block-editor/src/store/selectors.js

@@ -1357,8 +1357,11 @@ const getSelectedBlockAncestors = createSelector(
  * @return {boolean} Whether the block has an inner block selected
  */
 export function hasSelectedInnerBlock( state, clientId, deep = false ) {
-	const selectedBlockClientIds = getSelectedBlockClientIds( state );
+	if ( ! clientId ) {
+		return false;
+	}
 
+	const selectedBlockClientIds = getSelectedBlockClientIds( state );
 	if ( ! selectedBlockClientIds.length ) {
 		return false;
 	}