Editor: Exclude non-sticky posts in Query Loop Block when set to "Only".

Fixes a front-end issue to not include non-sticky posts in the Query Loop block when it's "Sticky Post" is set to "Only", meaning only show sticky posts.

This change was made in Gutenberg between 5.8 to 6.0, but was not merged into Core.

Reference:
* [42dad571ea/lib/compat/wordpress-6.1/blocks.php (L171-L183) Gutenberg code]

Follow-up to [50945].

Props RavanH, sc0ttkclark, ocean90, sc0ttkclark, hellofromTonya, ntsekouras.
Fixes #57822.
Built from https://develop.svn.wordpress.org/trunk@55447


git-svn-id: http://core.svn.wordpress.org/trunk@54980 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/blocks.php

@@ -1265,7 +1265,15 @@ function build_query_vars_from_query_block( $block, $page ) {
 		if ( isset( $block->context['query']['sticky'] ) && ! empty( $block->context['query']['sticky'] ) ) {
 			$sticky = get_option( 'sticky_posts' );
 			if ( 'only' === $block->context['query']['sticky'] ) {
-				$query['post__in'] = $sticky;
+				/*
+				 * Passing an empty array to post__in will return have_posts() as true (and all posts will be returned).
+				 * Logic should be used before hand to determine if WP_Query should be used in the event that the array
+				 * being passed to post__in is empty.
+				 *
+				 * @see https://core.trac.wordpress.org/ticket/28099
+				 */
+				$query['post__in']            = ! empty( $sticky ) ? $sticky : array( 0 );
+				$query['ignore_sticky_posts'] = 1;
 			} else {
 				$query['post__not_in'] = array_merge( $query['post__not_in'], $sticky );
 			}

wp-includes/version.php

@@ -16,7 +16,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '6.2-beta3-55446';
+$wp_version = '6.2-beta3-55447';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.