pass-author-name.diff

diff --git a/lib/rest-api.php b/lib/rest-api.php
index 8ad8653091..72944e6d79 100644
--- a/lib/rest-api.php
+++ b/lib/rest-api.php
@@ -52,6 +52,25 @@ function gutenberg_filter_oembed_result( $response, $handler, $request ) {
 }
 add_filter( 'rest_request_after_callbacks', 'gutenberg_filter_oembed_result', 10, 3 );
 
+add_action( 'rest_api_init', function() {
+	global $post;
+
+	if ( $post ) {
+		/**
+		 * Ensure the post author name is included in the user request.
+		 */
+		add_filter( "rest_prepare_{$post->post_type}", function( $response, $user, $request ) {
+			if ( $response->data['author'] ) {
+				$user = get_user_by( 'id', $response->data['author'] );
+				if ( $user ) {
+					$response->data[ 'author_name' ] = $user->data->display_name;
+				}
+			}
+			return $response;
+		}, 20, 3 );
+	}
+} );
+
 /**
  * Add fields required for site editing to the /themes endpoint.
  *
diff --git a/packages/editor/src/components/post-author/index.js b/packages/editor/src/components/post-author/index.js
index 90f3119e19..854bda7794 100644
--- a/packages/editor/src/components/post-author/index.js
+++ b/packages/editor/src/components/post-author/index.js
@@ -19,22 +19,20 @@ import PostAuthorCheck from './check';
 function PostAuthor() {
 	const [ fieldValue, setFieldValue ] = useState();
 
-	const { authorId, isLoading, authors, postAuthor } = useSelect(
+	const { authorId, isLoading, authors, authorName } = useSelect(
 		( select ) => {
-			const { __unstableGetAuthor, getAuthors, isResolving } = select(
+			const { getAuthors, isResolving } = select(
 				'core'
 			);
 			const { getEditedPostAttribute } = select( 'core/editor' );
-			const author =
-				postAuthor ||
-				__unstableGetAuthor( getEditedPostAttribute( 'author' ) )[ 0 ];
+			const author = { id: authorId, name: authorName };
 			const query =
 				! fieldValue || '' === fieldValue || fieldValue === author.name
 					? {}
 					: { search: fieldValue };
 			return {
 				authorId: getEditedPostAttribute( 'author' ),
-				postAuthor: author,
+				authorName: getEditedPostAttribute( 'author_name' ),
 				authors: getAuthors( query ),
 				isLoading: isResolving( 'core', 'getAuthors', [
 					{ search: fieldValue },
@@ -43,6 +41,7 @@ function PostAuthor() {
 		},
 		[ fieldValue ]
 	);
+	const postAuthor = { id: authorId, name: authorName };
 	const { editPost } = useDispatch( 'core/editor' );
 
 	const authorOptions = useMemo( () => {