Post Editor: fix click space after post content to append (#64992)

* Fix minimally

* Revise comment

* Stop propagation and don’t prevent default

* Insert default block if no blocks are present

packages/edit-post/src/components/layout/index.js

@@ -117,8 +117,8 @@ function useEditorStyles() {
 			? editorSettings.styles ?? []
 			: defaultEditorStyles;
 
-		// Add a constant padding for the typewriter effect. When typing at the
-		// bottom, there needs to be room to scroll up.
+		// Add a space for the typewriter effect. When typing in the last block,
+		// there needs to be room to scroll up.
 		if (
 			! isZoomedOutView &&
 			renderingMode === 'post-only' &&

packages/edit-post/src/components/layout/use-padding-appender.js

@@ -18,12 +18,12 @@ export function usePaddingAppender() {
 				const { ownerDocument } = node;
 				const { defaultView } = ownerDocument;
 
-				const paddingBottom = defaultView.parseInt(
-					defaultView.getComputedStyle( node ).paddingBottom,
+				const pseudoHeight = defaultView.parseInt(
+					defaultView.getComputedStyle( node, ':after' ).height,
 					10
 				);
 
-				if ( ! paddingBottom ) {
+				if ( ! pseudoHeight ) {
 					return;
 				}
 
@@ -38,25 +38,20 @@ export function usePaddingAppender() {
 					return;
 				}
 
-				event.preventDefault();
+				event.stopPropagation();
 
 				const blockOrder = registry
 					.select( blockEditorStore )
 					.getBlockOrder( '' );
 				const lastBlockClientId = blockOrder[ blockOrder.length - 1 ];
 
-				// Do nothing when only default block appender is present.
-				if ( ! lastBlockClientId ) {
-					return;
-				}
-
 				const lastBlock = registry
 					.select( blockEditorStore )
 					.getBlock( lastBlockClientId );
 				const { selectBlock, insertDefaultBlock } =
 					registry.dispatch( blockEditorStore );
 
-				if ( isUnmodifiedDefaultBlock( lastBlock ) ) {
+				if ( lastBlock && isUnmodifiedDefaultBlock( lastBlock ) ) {
 					selectBlock( lastBlockClientId );
 				} else {
 					insertDefaultBlock();